Always error on SizeOverflow during mir evaluation

Author: estebank

src/librustc/mir/interpret/error.rs

@@ -141,7 +141,6 @@ impl<'tcx> ConstEvalErr<'tcx> {
             err_inval!(Layout(LayoutError::Unknown(_))) |
             err_inval!(TooGeneric) =>
                 return Err(ErrorHandled::TooGeneric),
-            err_inval!(Layout(LayoutError::SizeOverflow(_))) |
             err_inval!(TypeckError) =>
                 return Err(ErrorHandled::Reported),
             _ => {},

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

@@ -0,0 +1,4 @@
+// error-pattern: reaching this expression at runtime will panic or abort
+fn main() {
+    println!("Size: {}", std::mem::size_of::<[u8; std::u64::MAX as usize]>());
+}

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

@@ -0,0 +1,15 @@
+error: 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])
+   | 
+  ::: $DIR/issue-55878.rs:3:26
+   |
+LL |     println!("Size: {}", std::mem::size_of::<[u8; std::u64::MAX as usize]>());
+   |                          ---------------------------------------------------
+   |
+   = note: `#[deny(const_err)]` on by default
+
+error: aborting due to previous error
+

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

@@ -17,6 +17,8 @@ impl TooBigArray {
 }
 
 static MY_TOO_BIG_ARRAY_1: TooBigArray = TooBigArray::new();
+//~^ ERROR could not evaluate static initializer
 static MY_TOO_BIG_ARRAY_2: [u8; HUGE_SIZE] = [0x00; HUGE_SIZE];
+//~^ ERROR could not evaluate static initializer
 
 fn main() { }

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

@@ -1,4 +1,15 @@
-error: the type `[u8; 2305843009213693951]` is too big for the current architecture
+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])
 
-error: aborting due to previous error
+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])
 
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0080`.