Auto merge of rust-lang#91205 - Aaron1011:visit_param_env, r=lcnr

Visit `param_env` field in Obligation's `TypeFoldable` impl

This oversight appears to have gone unnoticed for a long time
without causing issues, but it should still be fixed.

tests/ui/crashes/ice-6252.stderr

@@ -21,16 +21,15 @@ LL | impl<N, M> TypeVal<usize> for Multiply<N, M> where N: TypeVal<VAL> {}
    |          |
    |          help: you might be missing a type parameter: `, VAL`
 
-error[E0046]: not all trait items implemented, missing: `VAL`
-  --> $DIR/ice-6252.rs:10:1
+error[E0283]: type annotations needed
+  --> $DIR/ice-6252.rs:10:12
    |
-LL |     const VAL: T;
-   |     ------------- `VAL` from trait
-...
 LL | impl<N, M> TypeVal<usize> for Multiply<N, M> where N: TypeVal<VAL> {}
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ missing `VAL` in implementation
+   |            ^^^^^^^^^^^^^^ cannot infer type for struct `Multiply<N, M>`
+   |
+   = note: cannot satisfy `Multiply<N, M>: TypeVal<usize>`
 
 error: aborting due to 3 previous errors
 
-Some errors have detailed explanations: E0046, E0412.
-For more information about an error, try `rustc --explain E0046`.
+Some errors have detailed explanations: E0283, E0412.
+For more information about an error, try `rustc --explain E0283`.