Rollup merge of #70319 - lcnr:issue63695, r=eddyb

correctly normalize constants

closes #70317

implements https://github.com/rust-lang/rust/issues/70125#issuecomment-602133708

r? eddyb cc @varkor

src/test/mir-opt/inline/inline-into-box-place.rs

@@ -1,6 +1,7 @@
 // ignore-tidy-linelength
 // ignore-wasm32-bare compiled with panic=abort by default
 // compile-flags: -Z mir-opt-level=3
+// only-64bit FIXME: the mir representation of RawVec depends on ptr size
 #![feature(box_syntax)]
 
 fn main() {
@@ -55,7 +56,7 @@ fn main() {
 //   StorageLive(_2);
 //   _2 = Box(std::vec::Vec<u32>);
 //   _4 = &mut (*_2);
-//   ((*_4).0: alloc::raw_vec::RawVec<u32>) = const alloc::raw_vec::RawVec::<u32>::NEW;
+//   ((*_4).0: alloc::raw_vec::RawVec<u32>) = const ByRef { alloc: Allocation { bytes: [4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], relocations: Relocations(SortedMap { data: [] }), undef_mask: UndefMask { blocks: [65535], len: Size { raw: 16 } }, size: Size { raw: 16 }, align: Align { pow2: 3 }, mutability: Not, extra: () }, offset: Size { raw: 0 } }: alloc::raw_vec::RawVec::<u32>;
 //   ((*_4).1: usize) = const 0usize;
 //   _1 = move _2;
 //   StorageDead(_2);

src/test/ui/associated-const/defaults-cyclic-fail.rs

@@ -1,9 +1,9 @@
 // build-fail
+//~^ ERROR cycle detected when normalizing `<() as Tr>::A`
 
 // Cyclic assoc. const defaults don't error unless *used*
 trait Tr {
     const A: u8 = Self::B;
-    //~^ ERROR cycle detected when const-evaluating + checking `Tr::A`
 
     const B: u8 = Self::A;
 }

src/test/ui/associated-const/defaults-cyclic-fail.stderr

@@ -1,30 +1,42 @@
-error[E0391]: cycle detected when const-evaluating + checking `Tr::A`
-  --> $DIR/defaults-cyclic-fail.rs:5:5
+error[E0391]: cycle detected when normalizing `<() as Tr>::A`
+   |
+note: ...which requires const-evaluating + checking `Tr::A`...
+  --> $DIR/defaults-cyclic-fail.rs:6:5
    |
 LL |     const A: u8 = Self::B;
    |     ^^^^^^^^^^^^^^^^^^^^^^
-   |
-note: ...which requires const-evaluating `Tr::A`...
-  --> $DIR/defaults-cyclic-fail.rs:5:19
+note: ...which requires const-evaluating + checking `Tr::A`...
+  --> $DIR/defaults-cyclic-fail.rs:6:5
    |
 LL |     const A: u8 = Self::B;
-   |                   ^^^^^^^
+   |     ^^^^^^^^^^^^^^^^^^^^^^
+note: ...which requires const-evaluating `Tr::A`...
+  --> $DIR/defaults-cyclic-fail.rs:6:5
+   |
+LL |     const A: u8 = Self::B;
+   |     ^^^^^^^^^^^^^^^^^^^^^^
+   = note: ...which requires normalizing `<() as Tr>::B`...
+note: ...which requires const-evaluating + checking `Tr::B`...
+  --> $DIR/defaults-cyclic-fail.rs:8:5
+   |
+LL |     const B: u8 = Self::A;
+   |     ^^^^^^^^^^^^^^^^^^^^^^
 note: ...which requires const-evaluating + checking `Tr::B`...
   --> $DIR/defaults-cyclic-fail.rs:8:5
    |
 LL |     const B: u8 = Self::A;
    |     ^^^^^^^^^^^^^^^^^^^^^^
 note: ...which requires const-evaluating `Tr::B`...
-  --> $DIR/defaults-cyclic-fail.rs:8:19
+  --> $DIR/defaults-cyclic-fail.rs:8:5
    |
 LL |     const B: u8 = Self::A;
-   |                   ^^^^^^^
-   = note: ...which again requires const-evaluating + checking `Tr::A`, completing the cycle
+   |     ^^^^^^^^^^^^^^^^^^^^^^
+   = note: ...which again requires normalizing `<() as Tr>::A`, completing the cycle
 note: cycle used when const-evaluating `main`
-  --> $DIR/defaults-cyclic-fail.rs:16:16
+  --> $DIR/defaults-cyclic-fail.rs:14:1
    |
-LL |     assert_eq!(<() as Tr>::A, 0);
-   |                ^^^^^^^^^^^^^
+LL | fn main() {
+   | ^^^^^^^^^
 
 error: aborting due to previous error
 

src/test/ui/consts/const-size_of-cycle.stderr

@@ -25,7 +25,7 @@ note: ...which requires const-evaluating + checking `std::intrinsics::size_of`..
 LL |     pub fn size_of<T>() -> usize;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    = note: ...which requires computing layout of `Foo`...
-   = note: ...which requires normalizing `ParamEnvAnd { param_env: ParamEnv { caller_bounds: [], reveal: All, def_id: None }, value: [u8; _] }`...
+   = note: ...which requires normalizing `[u8; _]`...
    = note: ...which again requires const-evaluating + checking `Foo::bytes::{{constant}}#0`, completing the cycle
 note: cycle used when processing `Foo`
   --> $DIR/const-size_of-cycle.rs:7:1