[clang] [CIR] Fix 'vague' linkage globals. (PR #228586)

[Erich Keane via cfe-commits]

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@@ -215,6 +221,10 @@ struct LoweringPreparePass
                                     cir::IntType guardTy,
                                     cir::GlobalLinkageKind linkage);
 
+  /// Append 'global' to the module's llvm.used list to make sure it doesn't get
+  /// garbage-collected by the linker.
+  void addUsedGlobal(cir::GlobalOp global);
+
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erichkeane wrote:

Hmm... interesting, good catch, thanks!  I didn't spot that when messing around with github. 

https://github.com/llvm/llvm-project/pull/228586