[clang] [OpenACC] Add 'clause' parsing infrastructure plus a few clauses (PR #75052)

[via cfe-commits]

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@@ -208,6 +233,10 @@ OpenACCDirectiveKind ParseOpenACCDirectiveKind(Parser &P) {
   // introspect on the spelling before then.
   if (FirstTok.isNot(tok::identifier)) {
     P.Diag(FirstTok, diag::err_acc_missing_directive);
+
+    if (!FirstTok.isAnnotation())
+      P.ConsumeAnyToken();
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cor3ntin wrote:

I'm assuming that's for the end of pragma annotation. Shouldn't the test be more specific?

https://github.com/llvm/llvm-project/pull/75052