[clang] [clang][NFC] Refactor `clang/test/SemaCXX/type-traits.cpp` to use modern `static_assert` (PR #77584)

[Amirreza Ashouri via cfe-commits]

================
@@ -214,56 +212,56 @@ struct HasVirtBase : virtual ACompleteType {};
 
 void is_pod()
 {
-  { int arr[T(__is_pod(int))]; }
-  { int arr[T(__is_pod(Enum))]; }
-  { int arr[T(__is_pod(POD))]; }
-  { int arr[T(__is_pod(Int))]; }
-  { int arr[T(__is_pod(IntAr))]; }
-  { int arr[T(__is_pod(Statics))]; }
-  { int arr[T(__is_pod(Empty))]; }
-  { int arr[T(__is_pod(EmptyUnion))]; }
-  { int arr[T(__is_pod(Union))]; }
-  { int arr[T(__is_pod(HasFunc))]; }
-  { int arr[T(__is_pod(HasOp))]; }
-  { int arr[T(__is_pod(HasConv))]; }
-  { int arr[T(__is_pod(HasAssign))]; }
-  { int arr[T(__is_pod(IntArNB))]; }
-  { int arr[T(__is_pod(HasAnonymousUnion))]; }
-  { int arr[T(__is_pod(Vector))]; }
-  { int arr[T(__is_pod(VectorExt))]; }
-  { int arr[T(__is_pod(Derives))]; }
-  { int arr[T(__is_pod(DerivesAr))]; }
-  { int arr[T(__is_pod(DerivesArNB))]; }
-  { int arr[T(__is_pod(DerivesEmpty))]; }
-  { int arr[T(__is_pod(HasPriv))]; }
-  { int arr[T(__is_pod(HasProt))]; }
-  { int arr[T(__is_pod(DerivesHasPriv))]; }
-  { int arr[T(__is_pod(DerivesHasProt))]; }
-
-  { int arr[F(__is_pod(HasCons))]; }
-  { int arr[F(__is_pod(HasCopyAssign))]; }
-  { int arr[F(__is_pod(HasMoveAssign))]; }
-  { int arr[F(__is_pod(HasDest))]; }
-  { int arr[F(__is_pod(HasRef))]; }
-  { int arr[F(__is_pod(HasVirt))]; }
-  { int arr[F(__is_pod(DerivesHasCons))]; }
-  { int arr[F(__is_pod(DerivesHasCopyAssign))]; }
-  { int arr[F(__is_pod(DerivesHasMoveAssign))]; }
-  { int arr[F(__is_pod(DerivesHasDest))]; }
-  { int arr[F(__is_pod(DerivesHasRef))]; }
-  { int arr[F(__is_pod(DerivesHasVirt))]; }
-  { int arr[F(__is_pod(NonPOD))]; }
-  { int arr[F(__is_pod(HasNonPOD))]; }
-  { int arr[F(__is_pod(NonPODAr))]; }
-  { int arr[F(__is_pod(NonPODArNB))]; }
-  { int arr[F(__is_pod(void))]; }
-  { int arr[F(__is_pod(cvoid))]; }
-// { int arr[F(__is_pod(NonPODUnion))]; }
-
-  { int arr[T(__is_pod(ACompleteType))]; }
-  { int arr[F(__is_pod(AnIncompleteType))]; } // expected-error {{incomplete type}}
-  { int arr[F(__is_pod(AnIncompleteType[]))]; } // expected-error {{incomplete type}}
-  { int arr[F(__is_pod(AnIncompleteType[1]))]; } // expected-error {{incomplete type}}
+  static_assert(__is_pod(int), "");
----------------
AMP999 wrote:

Should we also remove the non-empty messages in the `__has_unique_object_representations` section? They seem mostly self-explanatory to me, and none of the other traits use non-empty messages. Like changing
`static_assert(!__has_unique_object_representations(PaddedBitfield), "Bitfield padding");` to `static_assert(!__has_unique_object_representations(PaddedBitfield));`

https://github.com/llvm/llvm-project/pull/77584