[clang] [OpenMP] Introduce support for OMPX extensions and taskgraph frontend (PR #66919)

[Alexey Bataev via cfe-commits]

================
@@ -1176,6 +1176,8 @@ def warn_pragma_ms_fenv_access : Warning<
 def warn_pragma_extra_tokens_at_eol : Warning<
   "extra tokens at end of '#pragma %0' - ignored">,
   InGroup<IgnoredPragmas>;
+def err_omp_extension_without_ompx : Error<
+  "Using extension directive '%0' in #pragma omp instead of #pragma ompx">;
----------------
alexey-bataev wrote:

Using -> unexpected?

https://github.com/llvm/llvm-project/pull/66919