Check that value is explicitly none

compiler/rustc_mir/src/transform/check_consts/qualifs.rs

@@ -246,8 +246,7 @@ where
     };
 
     // Check the qualifs of the value of `const` items.
-    if let ty::ConstKind::Unevaluated(def, _, promoted) = constant.literal.val {
-        assert!(promoted.is_none());
+    if let ty::ConstKind::Unevaluated(def, _, None) = constant.literal.val {
         // Don't peek inside trait associated constants.
         if cx.tcx.trait_of_item(def.did).is_none() {
             let qualifs = if let Some((did, param_did)) = def.as_const_arg() {

src/test/ui/issues/issue-80371.rs

@@ -0,0 +1,15 @@
+#![crate_type = "lib"]
+
+pub struct Header<'a> {
+    pub value: &'a [u8],
+}
+
+pub fn test() {
+    let headers = [Header{value: &[]}; 128];
+    //~^ ERROR the trait bound
+}
+
+pub fn test2() {
+    let headers = [Header{value: &[0]}; 128];
+    //~^ ERROR the trait bound
+}

src/test/ui/issues/issue-80371.stderr

@@ -0,0 +1,23 @@
+error[E0277]: the trait bound `Header<'_>: Copy` is not satisfied
+  --> $DIR/issue-80371.rs:8:19
+   |
+LL |     let headers = [Header{value: &[]}; 128];
+   |                   ^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `Header<'_>`
+   |
+   = note: the `Copy` trait is required because the repeated element will be copied
+   = note: this array initializer can be evaluated at compile-time, see issue #49147 <https://github.com/rust-lang/rust/issues/49147> for more information
+   = help: add `#![feature(const_in_array_repeat_expressions)]` to the crate attributes to enable
+
+error[E0277]: the trait bound `Header<'_>: Copy` is not satisfied
+  --> $DIR/issue-80371.rs:13:19
+   |
+LL |     let headers = [Header{value: &[0]}; 128];
+   |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `Header<'_>`
+   |
+   = note: the `Copy` trait is required because the repeated element will be copied
+   = note: this array initializer can be evaluated at compile-time, see issue #49147 <https://github.com/rust-lang/rust/issues/49147> for more information
+   = help: add `#![feature(const_in_array_repeat_expressions)]` to the crate attributes to enable
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0277`.