Enable ConstPropLint for promoteds

This fixes the issue wherein the lint didn't fire for promoteds
in the case of SHL/SHR operators in non-optimized builds
and all arithmetic operators in optimized builds

Author: gurry

compiler/rustc_mir_transform/src/const_prop_lint.rs

@@ -42,11 +42,6 @@ impl<'tcx> MirLint<'tcx> for ConstPropLint {
             return;
         }
 
-        // will be evaluated by miri and produce its errors there
-        if body.source.promoted.is_some() {
-            return;
-        }
-
         let def_id = body.source.def_id().expect_local();
         let def_kind = tcx.def_kind(def_id);
         let is_fn_like = def_kind.is_fn_like();

tests/ui/associated-consts/defaults-cyclic-fail.stderr

@@ -20,11 +20,11 @@ note: ...which requires const-evaluating + checking `Tr::B`...
 LL |     const B: u8 = Self::A;
    |                   ^^^^^^^
    = note: ...which again requires simplifying constant for the type system `Tr::A`, completing the cycle
-note: cycle used when const-evaluating + checking `main::promoted[1]`
-  --> $DIR/defaults-cyclic-fail.rs:16:16
+note: cycle used when simplifying constant for the type system `Tr::A`
+  --> $DIR/defaults-cyclic-fail.rs:5:5
    |
-LL |     assert_eq!(<() as Tr>::A, 0);
-   |                ^^^^^^^^^^^^^
+LL |     const A: u8 = Self::B;
+   |     ^^^^^^^^^^^
    = note: see https://rustc-dev-guide.rust-lang.org/overview.html#queries and https://rustc-dev-guide.rust-lang.org/query.html for more information
 
 error: aborting due to 1 previous error

tests/ui/associated-consts/defaults-not-assumed-fail.stderr

@@ -10,6 +10,14 @@ note: erroneous constant encountered
 LL |     assert_eq!(<() as Tr>::B, 0);    // causes the error above
    |                ^^^^^^^^^^^^^
 
+note: erroneous constant encountered
+  --> $DIR/defaults-not-assumed-fail.rs:33:16
+   |
+LL |     assert_eq!(<() as Tr>::B, 0);    // causes the error above
+   |                ^^^^^^^^^^^^^
+   |
+   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+
 note: erroneous constant encountered
   --> $DIR/defaults-not-assumed-fail.rs:33:5
    |

tests/ui/consts/const-eval/issue-44578.stderr

@@ -10,6 +10,14 @@ note: erroneous constant encountered
 LL |     println!("{}", <Bar<u16, u8> as Foo>::AMT);
    |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
+note: erroneous constant encountered
+  --> $DIR/issue-44578.rs:25:20
+   |
+LL |     println!("{}", <Bar<u16, u8> as Foo>::AMT);
+   |                    ^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |
+   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+
 note: erroneous constant encountered
   --> $DIR/issue-44578.rs:25:20
    |

tests/ui/consts/const-eval/issue-50814.stderr

@@ -10,12 +10,28 @@ note: erroneous constant encountered
 LL |     &Sum::<U8, U8>::MAX
    |      ^^^^^^^^^^^^^^^^^^
 
+error[E0080]: evaluation of `<Sum<U8, U8> as Unsigned>::MAX` failed
+  --> $DIR/issue-50814.rs:15:21
+   |
+LL |     const MAX: u8 = A::MAX + B::MAX;
+   |                     ^^^^^^^^^^^^^^^ attempt to compute `u8::MAX + u8::MAX`, which would overflow
+   |
+   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+
+note: erroneous constant encountered
+  --> $DIR/issue-50814.rs:20:6
+   |
+LL |     &Sum::<U8, U8>::MAX
+   |      ^^^^^^^^^^^^^^^^^^
+   |
+   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
+
 note: the above error was encountered while instantiating `fn foo::<i32>`
   --> $DIR/issue-50814.rs:25:5
    |
 LL |     foo(0);
    |     ^^^^^^
 
-error: aborting due to 1 previous error
+error: aborting due to 2 previous errors
 
 For more information about this error, try `rustc --explain E0080`.