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

[Sean Perry via cfe-commits]

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@@ -2314,6 +2314,23 @@ class Sema final : public SemaBase {
   ActOnPragmaMSFunction(SourceLocation Loc,
                         const llvm::SmallVectorImpl<StringRef> &NoBuiltins);
 
+  NamedDecl *lookupExternCFunctionOrVariable(IdentifierInfo *IdentId,
+                                             SourceLocation NameLoc,
+                                             Scope *curScope);
+
+  /// A label from a C++ #pragma export, for a symbol that we
+  /// haven't seen the declaration for yet.
+  struct SymbolLabel {
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perry-ca wrote:

I renamed the class `PendingPragmaInfo`.  I left "export" out of the name as I have another pragma (called map) that I'm going to upstream after this one.  Let me know if you're ok with that.

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