Note when a a move/borrow error is caused by a deref coercion

Fixes #73268

When a deref coercion occurs, we may end up with a move error if the
base value has been partially moved out of. However, we do not indicate
anywhere that a deref coercion is occuring, resulting in an error
message with a confusing span.

This PR adds an explicit note to move errors when a deref coercion is
involved. We mention the name of the type that the deref-coercion
resolved to, as well as the `Deref::Target` associated type being used.

compiler/rustc_mir/src/transform/check_const_item_mutation.rs

@@ -101,7 +101,7 @@ impl<'a, 'tcx> Visitor<'tcx> for ConstMutationChecker<'a, 'tcx> {
                         .note("each usage of a `const` item creates a new temporary")
                         .note("the mutable reference will refer to this temporary, not the original `const` item");
 
-                    if let Some(method_did) = method_did {
+                    if let Some((method_did, _substs)) = method_did {
                         lint.span_note(self.tcx.def_span(method_did), "mutable reference created due to call to this method");
                     }