rustc_codegen_ssa: Don't let IncorrectCguReuseType errors get lost

In [100753], `IncorrectCguReuseType` accidentally stopped being emitted.
Begin emitting it again rather than just blindly dropping it, and adjust
tests accordingly.

[100753]: 706452eba7 (diff-048389738ddcbe0f9765291a29db1fed9a5f03693d4781cfb5aaa97ffb3c7f84)

compiler/rustc_codegen_ssa/src/assert_module_sources.rs

@@ -278,13 +278,13 @@ impl CguReuseTracker {
 
                     if error {
                         let at_least = if at_least { 1 } else { 0 };
-                        errors::IncorrectCguReuseType {
+                        sess.emit_err(errors::IncorrectCguReuseType {
                             span: *error_span,
                             cgu_user_name,
                             actual_reuse,
                             expected_reuse,
                             at_least,
-                        };
+                        });
                     }
                 } else {
                     sess.emit_fatal(errors::CguNotRecorded { cgu_user_name, cgu_name });