Relocate 5 tests from tests/ui/issues

Relocate issues/issue-51154.rs to closures/box-generic-closure.rs

Relocate issues/issue-51515.rs to
borrowck/assignment-to-immutable-ref.rs

Relocate issues/issue-53348.rs to mismatched_types/deref-string-assign.rs

Relocate issues/issue-52717.rs to
pattern/match-enum-struct-variant-field-missing.rs

Relocate issues/issue-53300.rs to
type/cannot-find-wrapper-with-impl-trait.rs

tests/ui/borrowck/assignment-to-immutable-ref.rs

@@ -1,3 +1,7 @@
+//! Regression test for issue <https://github.com/rust-lang/rust/issues/51515>
+//! Test that assigning through an immutable reference (`&`) correctly yields
+//! an assignment error (E0594) and suggests using a mutable reference.
+
 fn main() {
     let foo = &16;
     //~^ HELP consider changing this to be a mutable reference

tests/ui/borrowck/assignment-to-immutable-ref.stderr

@@ -1,5 +1,5 @@
 error[E0594]: cannot assign to `*foo`, which is behind a `&` reference
-  --> $DIR/issue-51515.rs:4:5
+  --> $DIR/assignment-to-immutable-ref.rs:8:5
    |
 LL |     *foo = 32;
    |     ^^^^^^^^^ `foo` is a `&` reference, so it cannot be written to
@@ -10,7 +10,7 @@ LL |     let foo = &mut 16;
    |                +++
 
 error[E0594]: cannot assign to `*bar`, which is behind a `&` reference
-  --> $DIR/issue-51515.rs:8:5
+  --> $DIR/assignment-to-immutable-ref.rs:12:5
    |
 LL |     *bar = 64;
    |     ^^^^^^^^^ `bar` is a `&` reference, so it cannot be written to

tests/ui/closures/box-generic-closure.rs

@@ -0,0 +1,10 @@
+//! Regression test for issue <https://github.com/rust-lang/rust/issues/51154>
+//! Test that anonymous closure types cannot be coerced to a generic type
+//! parameter (F: FnMut()) when trying to box them.
+
+fn foo<F: FnMut()>() {
+    let _: Box<F> = Box::new(|| ());
+    //~^ ERROR mismatched types
+}
+
+fn main() {}

tests/ui/closures/box-generic-closure.stderr

@@ -1,5 +1,5 @@
 error[E0308]: mismatched types
-  --> $DIR/issue-51154.rs:2:30
+  --> $DIR/box-generic-closure.rs:6:30
    |
 LL | fn foo<F: FnMut()>() {
    |        - expected this type parameter
@@ -9,7 +9,7 @@ LL |     let _: Box<F> = Box::new(|| ());
    |                     arguments to this function are incorrect
    |
    = note: expected type parameter `F`
-                     found closure `{closure@$DIR/issue-51154.rs:2:30: 2:32}`
+                     found closure `{closure@$DIR/box-generic-closure.rs:6:30: 6:32}`
    = help: every closure has a distinct type and so could not always match the caller-chosen type of parameter `F`
 note: associated function defined here
   --> $SRC_DIR/alloc/src/boxed.rs:LL:COL

tests/ui/issues/issue-51154.rs

@@ -1,6 +0,0 @@
-fn foo<F: FnMut()>() {
-    let _: Box<F> = Box::new(|| ());
-    //~^ ERROR mismatched types
-}
-
-fn main() {}

tests/ui/issues/issue-52717.rs

@@ -1,13 +0,0 @@
-enum A {
-  A {
-    foo: usize,
-  }
-}
-
-fn main() {
-  let x = A::A { foo: 3 };
-  match x {
-    A::A { fob } => { println!("{}", fob); }
-//~^ ERROR does not have a field named `fob`
-  }
-}

tests/ui/issues/issue-52717.stderr

@@ -1,12 +0,0 @@
-error[E0026]: variant `A::A` does not have a field named `fob`
-  --> $DIR/issue-52717.rs:10:12
-   |
-LL |     A::A { fob } => { println!("{}", fob); }
-   |            ^^^
-   |            |
-   |            variant `A::A` does not have this field
-   |            help: a field with a similar name exists: `foo`
-
-error: aborting due to 1 previous error
-
-For more information about this error, try `rustc --explain E0026`.

tests/ui/mismatched_types/assign-deref-string-to-string.rs

@@ -1,9 +1,13 @@
+//! Regression test for issue https://github.com/rust-lang/rust/issues/53348
+//! Test that attempting to assign a dereferenced `String` (which is `str`)
+//! to a `String` variable correctly results in a mismatched types error (E0308).
+
 fn main() {
     let mut v = vec!["hello", "this", "is", "a", "test"];
 
     let v2 = Vec::new();
 
-    v.into_iter().map(|s|s.to_owned()).collect::<Vec<_>>();
+    v.into_iter().map(|s| s.to_owned()).collect::<Vec<_>>();
 
     let mut a = String::new(); //~ NOTE expected due to this value
     for i in v {

tests/ui/mismatched_types/assign-deref-string-to-string.stderr

@@ -1,5 +1,5 @@
 error[E0308]: mismatched types
-  --> $DIR/issue-53348.rs:10:13
+  --> $DIR/assign-deref-string-to-string.rs:14:13
    |
 LL |     let mut a = String::new();
    |                 ------------- expected due to this value

tests/ui/pattern/match-enum-struct-variant-field-missing.rs

@@ -0,0 +1,17 @@
+//! Regression test for issue <https://github.com/rust-lang/rust/issues/52717>
+//! Test that matching an enum struct variant with a missing or incorrect field name
+//! correctly yields a "does not have a field named" error.
+
+enum A {
+    A { foo: usize },
+}
+
+fn main() {
+    let x = A::A { foo: 3 };
+    match x {
+        A::A { fob } => {
+            //~^ ERROR does not have a field named `fob`
+            println!("{fob}");
+        }
+    }
+}

tests/ui/pattern/match-enum-struct-variant-field-missing.stderr

@@ -0,0 +1,12 @@
+error[E0026]: variant `A::A` does not have a field named `fob`
+  --> $DIR/match-enum-struct-variant-field-missing.rs:12:16
+   |
+LL |         A::A { fob } => {
+   |                ^^^
+   |                |
+   |                variant `A::A` does not have this field
+   |                help: a field with a similar name exists: `foo`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0026`.

tests/ui/type/cannot-find-wrapper-with-impl-trait.rs

@@ -1,4 +1,5 @@
-// issue 53300
+//! Regression test for issue <https://github.com/rust-lang/rust/issues/53300>
+//! Tests that an undefined type (Wrapper) used with impl Trait correctly gives E0412.
 
 pub trait A {
     fn add(&self, b: i32) -> i32;

tests/ui/type/cannot-find-wrapper-with-impl-trait.stderr

@@ -1,5 +1,5 @@
 error[E0412]: cannot find type `Wrapper` in this scope
-  --> $DIR/issue-53300.rs:7:18
+  --> $DIR/cannot-find-wrapper-with-impl-trait.rs:8:18
    |
 LL | fn addition() -> Wrapper<impl A> {}
    |                  ^^^^^^^ not found in this scope