[clang] [SystemZ][z/OS] Implement #pragma export (PR #141671)

[Erich Keane via cfe-commits]

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@@ -568,6 +574,11 @@ void Parser::initializePragmaHandlers() {
   MaxTokensTotalPragmaHandler = std::make_unique<PragmaMaxTokensTotalHandler>();
   PP.AddPragmaHandler("clang", MaxTokensTotalPragmaHandler.get());
 
+  if (getLangOpts().ZOSExt) {
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erichkeane wrote:

This isn't particularly ZOS specific other than for compiler compat, right?  Is there a good reason we couldn't allow this syntax on other compilers?

https://github.com/llvm/llvm-project/pull/141671