Store idents for DefPathData into crate metadata

Previously, we threw away the `Span` associated with a definition's
identifier when we encoded crate metadata, causing us to lose location
and hygiene information.

We now store the identifier's `Span` in the crate metadata.
When we decode items from the metadata, we combine
the name and span back into an `Ident`.

This improves the output of several tests, which previously had messages
suppressed due to dummy spans.

This is a prerequisite for #68686, since throwing away a `Span` means
that we lose hygiene information.

src/test/ui/copy-a-resource.stderr

@@ -6,6 +6,14 @@ LL | struct Foo {
 ...
 LL |     let _y = x.clone();
    |                ^^^^^ method not found in `Foo`
+   | 
+  ::: $SRC_DIR/libcore/clone.rs:LL:COL
+   |
+LL |     fn clone(&self) -> Self;
+   |        -----
+   |        |
+   |        the method is available for `std::sync::Arc<Foo>` here
+   |        the method is available for `std::rc::Rc<Foo>` here
    |
    = help: items from traits can only be used if the trait is implemented and in scope
    = note: the following trait defines an item `clone`, perhaps you need to implement it:

src/test/ui/derives/derive-assoc-type-not-impl.stderr

@@ -12,6 +12,14 @@ LL | struct NotClone;
 ...
 LL |     Bar::<NotClone> { x: 1 }.clone();
    |                              ^^^^^ method not found in `Bar<NotClone>`
+   | 
+  ::: $SRC_DIR/libcore/clone.rs:LL:COL
+   |
+LL |     fn clone(&self) -> Self;
+   |        -----
+   |        |
+   |        the method is available for `std::sync::Arc<Bar<NotClone>>` here
+   |        the method is available for `std::rc::Rc<Bar<NotClone>>` here
    |
    = note: the method `clone` exists but the following trait bounds were not satisfied:
            `NotClone: std::clone::Clone`

src/test/ui/error-codes/E0004-2.stderr

@@ -3,6 +3,14 @@ error[E0004]: non-exhaustive patterns: `None` and `Some(_)` not covered
    |
 LL |     match x { }
    |           ^ patterns `None` and `Some(_)` not covered
+   | 
+  ::: $SRC_DIR/libcore/option.rs:LL:COL
+   |
+LL |     None,
+   |     ---- not covered
+...
+LL |     Some(#[stable(feature = "rust1", since = "1.0.0")] T),
+   |     ---- not covered
    |
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 

src/test/ui/error-codes/E0005.stderr

@@ -3,6 +3,11 @@ error[E0005]: refutable pattern in local binding: `None` not covered
    |
 LL |     let Some(y) = x;
    |         ^^^^^^^ pattern `None` not covered
+   | 
+  ::: $SRC_DIR/libcore/option.rs:LL:COL
+   |
+LL |     None,
+   |     ---- not covered
    |
    = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant
    = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html

src/test/ui/error-codes/E0297.stderr

@@ -3,6 +3,11 @@ error[E0005]: refutable pattern in `for` loop binding: `None` not covered
    |
 LL |     for Some(x) in xs {}
    |         ^^^^^^^ pattern `None` not covered
+   | 
+  ::: $SRC_DIR/libcore/option.rs:LL:COL
+   |
+LL |     None,
+   |     ---- not covered
 
 error: aborting due to previous error
 

src/test/ui/feature-gates/feature-gate-exhaustive-patterns.stderr

@@ -3,6 +3,11 @@ error[E0005]: refutable pattern in local binding: `Err(_)` not covered
    |
 LL |     let Ok(_x) = foo();
    |         ^^^^^^ pattern `Err(_)` not covered
+   | 
+  ::: $SRC_DIR/libcore/result.rs:LL:COL
+   |
+LL |     Err(#[stable(feature = "rust1", since = "1.0.0")] E),
+   |     --- not covered
    |
    = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant
    = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html

src/test/ui/generic-associated-types/iterable.stderr

@@ -5,6 +5,11 @@ LL | impl<T> Iterable for Vec<T> {
    | --------------------------- in this `impl` item
 LL |     type Item<'a> where T: 'a = <std::slice::Iter<'a, T> as Iterator>::Item;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected reference, found associated type
+   | 
+  ::: $SRC_DIR/libcore/iter/traits/iterator.rs:LL:COL
+   |
+LL |     type Item;
+   |          ---- associated type defined here
    |
    = note:    expected reference `&T`
            found associated type `<std::vec::Vec<T> as Iterable>::Item<'_>`
@@ -18,6 +23,11 @@ LL | impl<T> Iterable for [T] {
    | ------------------------ in this `impl` item
 LL |     type Item<'a> where T: 'a = <std::slice::Iter<'a, T> as Iterator>::Item;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected reference, found associated type
+   | 
+  ::: $SRC_DIR/libcore/iter/traits/iterator.rs:LL:COL
+   |
+LL |     type Item;
+   |          ---- associated type defined here
    |
    = note:    expected reference `&T`
            found associated type `<[T] as Iterable>::Item<'_>`

src/test/ui/impl-trait/no-method-suggested-traits.stderr

@@ -83,6 +83,16 @@ error[E0599]: no method named `method` found for struct `std::rc::Rc<&mut std::b
    |
 LL |     std::rc::Rc::new(&mut Box::new(&1i32)).method();
    |                                            ^^^^^^ method not found in `std::rc::Rc<&mut std::boxed::Box<&i32>>`
+   | 
+  ::: $DIR/auxiliary/no_method_suggested_traits.rs:8:12
+   |
+LL |         fn method(&self) {}
+   |            ------
+   |            |
+   |            the method is available for `std::boxed::Box<std::rc::Rc<&mut std::boxed::Box<&i32>>>` here
+   |            the method is available for `std::pin::Pin<std::rc::Rc<&mut std::boxed::Box<&i32>>>` here
+   |            the method is available for `std::sync::Arc<std::rc::Rc<&mut std::boxed::Box<&i32>>>` here
+   |            the method is available for `std::rc::Rc<std::rc::Rc<&mut std::boxed::Box<&i32>>>` here
    |
    = help: items from traits can only be used if the trait is in scope
 help: the following trait is implemented but not in scope; perhaps add a `use` for it:

src/test/ui/issues/issue-2823.stderr

@@ -6,6 +6,14 @@ LL | struct C {
 ...
 LL |     let _d = c.clone();
    |                ^^^^^ method not found in `C`
+   | 
+  ::: $SRC_DIR/libcore/clone.rs:LL:COL
+   |
+LL |     fn clone(&self) -> Self;
+   |        -----
+   |        |
+   |        the method is available for `std::sync::Arc<C>` here
+   |        the method is available for `std::rc::Rc<C>` here
    |
    = help: items from traits can only be used if the trait is implemented and in scope
    = note: the following trait defines an item `clone`, perhaps you need to implement it:

src/test/ui/issues/issue-69725.stderr

@@ -8,6 +8,14 @@ LL |     let _ = Struct::<A>::new().clone();
    |
 LL | pub struct Struct<A>(A);
    | ------------------------ doesn't satisfy `issue_69725::Struct<A>: std::clone::Clone`
+   | 
+  ::: $SRC_DIR/libcore/clone.rs:LL:COL
+   |
+LL |     fn clone(&self) -> Self;
+   |        -----
+   |        |
+   |        the method is available for `std::sync::Arc<issue_69725::Struct<A>>` here
+   |        the method is available for `std::rc::Rc<issue_69725::Struct<A>>` here
    |
    = note: the method `clone` exists but the following trait bounds were not satisfied:
            `A: std::clone::Clone`

src/test/ui/non-copyable-void.stderr

@@ -3,6 +3,14 @@ error[E0599]: no method named `clone` found for enum `libc::c_void` in the curre
    |
 LL |         let _z = (*y).clone();
    |                       ^^^^^ method not found in `libc::c_void`
+   | 
+  ::: $SRC_DIR/libcore/clone.rs:LL:COL
+   |
+LL |     fn clone(&self) -> Self;
+   |        -----
+   |        |
+   |        the method is available for `std::sync::Arc<libc::c_void>` here
+   |        the method is available for `std::rc::Rc<libc::c_void>` here
 
 error: aborting due to previous error
 

src/test/ui/noncopyable-class.stderr

@@ -6,6 +6,14 @@ LL | struct Foo {
 ...
 LL |     let _y = x.clone();
    |                ^^^^^ method not found in `Foo`
+   | 
+  ::: $SRC_DIR/libcore/clone.rs:LL:COL
+   |
+LL |     fn clone(&self) -> Self;
+   |        -----
+   |        |
+   |        the method is available for `std::sync::Arc<Foo>` here
+   |        the method is available for `std::rc::Rc<Foo>` here
    |
    = help: items from traits can only be used if the trait is implemented and in scope
    = note: the following trait defines an item `clone`, perhaps you need to implement it:

src/test/ui/pattern/usefulness/match-arm-statics-2.stderr

@@ -11,6 +11,14 @@ error[E0004]: non-exhaustive patterns: `Some(Some(West))` not covered
    |
 LL |     match Some(Some(North)) {
    |           ^^^^^^^^^^^^^^^^^ pattern `Some(Some(West))` not covered
+   | 
+  ::: $SRC_DIR/libcore/option.rs:LL:COL
+   |
+LL |     Some(#[stable(feature = "rust1", since = "1.0.0")] T),
+   |     ----
+   |     |
+   |     not covered
+   |     not covered
    |
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 

src/test/ui/pattern/usefulness/match-privately-empty.stderr

@@ -3,6 +3,11 @@ error[E0004]: non-exhaustive patterns: `Some(Private { misc: true, .. })` not co
    |
 LL |     match private::DATA {
    |           ^^^^^^^^^^^^^ pattern `Some(Private { misc: true, .. })` not covered
+   | 
+  ::: $SRC_DIR/libcore/option.rs:LL:COL
+   |
+LL |     Some(#[stable(feature = "rust1", since = "1.0.0")] T),
+   |     ---- not covered
    |
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 

src/test/ui/pattern/usefulness/non-exhaustive-match.stderr

@@ -25,6 +25,11 @@ error[E0004]: non-exhaustive patterns: `Some(_)` not covered
    |
 LL |     match Some(10) {
    |           ^^^^^^^^ pattern `Some(_)` not covered
+   | 
+  ::: $SRC_DIR/libcore/option.rs:LL:COL
+   |
+LL |     Some(#[stable(feature = "rust1", since = "1.0.0")] T),
+   |     ---- not covered
    |
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 

src/test/ui/recursion/recursive-types-are-not-uninhabited.stderr

@@ -3,6 +3,11 @@ error[E0005]: refutable pattern in local binding: `Err(_)` not covered
    |
 LL |     let Ok(x) = res;
    |         ^^^^^ pattern `Err(_)` not covered
+   | 
+  ::: $SRC_DIR/libcore/result.rs:LL:COL
+   |
+LL |     Err(#[stable(feature = "rust1", since = "1.0.0")] E),
+   |     --- not covered
    |
    = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant
    = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html

src/test/ui/resolve/issue-3907-2.stderr

@@ -3,8 +3,11 @@ error[E0038]: the trait `issue_3907::Foo` cannot be made into an object
    |
 LL | fn bar(_x: Foo) {}
    |            ^^^ the trait `issue_3907::Foo` cannot be made into an object
+   | 
+  ::: $DIR/auxiliary/issue-3907.rs:2:8
    |
-   = note: the trait cannot be made into an object because associated function `bar` has no `self` parameter
+LL |     fn bar();
+   |        --- the trait cannot be made into an object because associated function `bar` has no `self` parameter
 
 error: aborting due to previous error
 

src/test/ui/rfc-2008-non-exhaustive/uninhabited/match.stderr

@@ -27,6 +27,13 @@ error[E0004]: non-exhaustive patterns: `Tuple(_)` and `Struct { .. }` not covere
    |
 LL |     match x {}
    |           ^ patterns `Tuple(_)` and `Struct { .. }` not covered
+   | 
+  ::: $DIR/auxiliary/uninhabited.rs:17:23
+   |
+LL |     #[non_exhaustive] Tuple(!),
+   |                       ----- not covered
+LL |     #[non_exhaustive] Struct { x: ! }
+   |                       ------ not covered
    |
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 

src/test/ui/rfc-2008-non-exhaustive/uninhabited/match_with_exhaustive_patterns.stderr

@@ -27,6 +27,13 @@ error[E0004]: non-exhaustive patterns: `Tuple(_)` and `Struct { .. }` not covere
    |
 LL |     match x {}
    |           ^ patterns `Tuple(_)` and `Struct { .. }` not covered
+   | 
+  ::: $DIR/auxiliary/uninhabited.rs:17:23
+   |
+LL |     #[non_exhaustive] Tuple(!),
+   |                       ----- not covered
+LL |     #[non_exhaustive] Struct { x: ! }
+   |                       ------ not covered
    |
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 

src/test/ui/uninhabited/uninhabited-matches-feature-gated.stderr

@@ -3,6 +3,11 @@ error[E0004]: non-exhaustive patterns: `Err(_)` not covered
    |
 LL |     let _ = match x {
    |                   ^ pattern `Err(_)` not covered
+   | 
+  ::: $SRC_DIR/libcore/result.rs:LL:COL
+   |
+LL |     Err(#[stable(feature = "rust1", since = "1.0.0")] E),
+   |     --- not covered
    |
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
@@ -46,6 +51,11 @@ error[E0004]: non-exhaustive patterns: `Err(_)` not covered
    |
 LL |     let _ = match x {
    |                   ^ pattern `Err(_)` not covered
+   | 
+  ::: $SRC_DIR/libcore/result.rs:LL:COL
+   |
+LL |     Err(#[stable(feature = "rust1", since = "1.0.0")] E),
+   |     --- not covered
    |
    = help: ensure that all possible cases are being handled, possibly by adding wildcards or more match arms
 
@@ -54,6 +64,11 @@ error[E0005]: refutable pattern in local binding: `Err(_)` not covered
    |
 LL |     let Ok(x) = x;
    |         ^^^^^ pattern `Err(_)` not covered
+   | 
+  ::: $SRC_DIR/libcore/result.rs:LL:COL
+   |
+LL |     Err(#[stable(feature = "rust1", since = "1.0.0")] E),
+   |     --- not covered
    |
    = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant
    = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html

src/test/ui/union/union-derive-clone.stderr

@@ -21,6 +21,14 @@ LL | struct CloneNoCopy;
 ...
 LL |     let w = u.clone();
    |               ^^^^^ method not found in `U5<CloneNoCopy>`
+   | 
+  ::: $SRC_DIR/libcore/clone.rs:LL:COL
+   |
+LL |     fn clone(&self) -> Self;
+   |        -----
+   |        |
+   |        the method is available for `std::sync::Arc<U5<CloneNoCopy>>` here
+   |        the method is available for `std::rc::Rc<U5<CloneNoCopy>>` here
    |
    = note: the method `clone` exists but the following trait bounds were not satisfied:
            `CloneNoCopy: std::marker::Copy`

src/test/ui/unique-object-noncopyable.stderr

@@ -14,6 +14,14 @@ LL |     let _z = y.clone();
    |
 LL | pub struct Box<T: ?Sized>(Unique<T>);
    | ------------------------------------- doesn't satisfy `std::boxed::Box<dyn Foo>: std::clone::Clone`
+   | 
+  ::: $SRC_DIR/libcore/clone.rs:LL:COL
+   |
+LL |     fn clone(&self) -> Self;
+   |        -----
+   |        |
+   |        the method is available for `std::sync::Arc<std::boxed::Box<dyn Foo>>` here
+   |        the method is available for `std::rc::Rc<std::boxed::Box<dyn Foo>>` here
    |
    = note: the method `clone` exists but the following trait bounds were not satisfied:
            `dyn Foo: std::marker::Sized`

src/test/ui/unique-pinned-nocopy.stderr

@@ -11,6 +11,14 @@ LL |     let _j = i.clone();
    |
 LL | pub struct Box<T: ?Sized>(Unique<T>);
    | ------------------------------------- doesn't satisfy `std::boxed::Box<R>: std::clone::Clone`
+   | 
+  ::: $SRC_DIR/libcore/clone.rs:LL:COL
+   |
+LL |     fn clone(&self) -> Self;
+   |        -----
+   |        |
+   |        the method is available for `std::sync::Arc<std::boxed::Box<R>>` here
+   |        the method is available for `std::rc::Rc<std::boxed::Box<R>>` here
    |
    = note: the method `clone` exists but the following trait bounds were not satisfied:
            `R: std::clone::Clone`