[clang] [libcxx] [libc++][Clang] Updated the diagnostics checks in libc++ tests. (PR #144220)

[Nikolas Klauser via cfe-commits]

================
@@ -55,6 +55,7 @@ void test() {
       // expected-error-re@*:* {{static assertion failed {{.*}}The result of f(value()) must be a specialization of std::expected}}
       // expected-error-re@*:* {{{{.*}}cannot be used prior to '::' because it has no members}}
       // expected-error-re@*:* {{no matching constructor for initialization of{{.*}}}}
+      // expected-error@*:* {{excess elements in struct initializer}}
----------------
philnik777 wrote:

This looks fishy. Why are there more errors now? I though this should only add notes explaining what happened.

https://github.com/llvm/llvm-project/pull/144220