[clang] [OpenACC][NFC] Add OpenACC Clause AST Nodes/infrastructure (PR #87675)

[Erich Keane via cfe-commits]

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@@ -94,9 +94,10 @@ StmtResult SemaOpenACC::ActOnEndStmtDirective(OpenACCDirectiveKind K,
   case OpenACCDirectiveKind::Parallel:
   case OpenACCDirectiveKind::Serial:
   case OpenACCDirectiveKind::Kernels:
+    // TODO OpenACC: Add clauses to the construct here.
     return OpenACCComputeConstruct::Create(
         getASTContext(), K, StartLoc, EndLoc,
-        AssocStmt.isUsable() ? AssocStmt.get() : nullptr);
+        /*Clauses=*/{}, AssocStmt.isUsable() ? AssocStmt.get() : nullptr);
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erichkeane wrote:

Making the change (assuming it builds:) )  But curious as to why the nullopt preference here?  Both create an 'empty' `ArrayRef`, right?

https://github.com/llvm/llvm-project/pull/87675