Nicer labels for type layout errors

Author: estebank

src/librustc/mir/interpret/error.rs

@@ -144,7 +144,7 @@ impl<'tcx> ConstEvalErr<'tcx> {
                 return Err(ErrorHandled::TooGeneric),
             err_inval!(TypeckError) =>
                 return Err(ErrorHandled::Reported),
-            err_inval!(LayoutError::SizeOverflow(_)) => must_error = true,
+            err_inval!(Layout(LayoutError::SizeOverflow(_))) => must_error = true,
             _ => {},
         }
         trace!("reporting const eval failure at {:?}", self.span);
@@ -336,7 +336,7 @@ impl fmt::Debug for InvalidProgramInfo<'tcx> {
             TypeckError =>
                 write!(f, "encountered constants with type errors, stopping evaluation"),
             Layout(ref err) =>
-                write!(f, "rustc layout computation failed: {:?}", err),
+                write!(f, "{}", err),
         }
     }
 }

src/test/ui/consts/issue-55878.stderr

@@ -2,7 +2,7 @@ error[E0080]: reaching this expression at runtime will panic or abort
   --> $SRC_DIR/libcore/mem/mod.rs:LL:COL
    |
 LL |     intrinsics::size_of::<T>()
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ rustc layout computation failed: SizeOverflow([u8; 18446744073709551615])
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^ the type `[u8; 18446744073709551615]` is too big for the current architecture
    | 
   ::: $DIR/issue-55878.rs:3:26
    |

src/test/ui/issues/issue-56762.stderr

@@ -2,13 +2,13 @@ error[E0080]: could not evaluate static initializer
   --> $DIR/issue-56762.rs:19:1
    |
 LL | static MY_TOO_BIG_ARRAY_1: TooBigArray = TooBigArray::new();
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ rustc layout computation failed: SizeOverflow([u8; 2305843009213693951])
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the type `[u8; 2305843009213693951]` is too big for the current architecture
 
 error[E0080]: could not evaluate static initializer
   --> $DIR/issue-56762.rs:21:1
    |
 LL | static MY_TOO_BIG_ARRAY_2: [u8; HUGE_SIZE] = [0x00; HUGE_SIZE];
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ rustc layout computation failed: SizeOverflow([u8; 2305843009213693951])
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the type `[u8; 2305843009213693951]` is too big for the current architecture
 
 error: aborting due to 2 previous errors