[llvm] [clang] [clang][llvm][fatlto] Avoid cloning modules in FatLTO (PR #72180)

[Teresa Johnson via cfe-commits]

================
@@ -810,7 +810,7 @@ void EmitAssemblyHelper::RunOptimizationPipeline(
   // Only enable CGProfilePass when using integrated assembler, since
   // non-integrated assemblers don't recognize .cgprofile section.
   PTO.CallGraphProfile = !CodeGenOpts.DisableIntegratedAS;
-  PTO.UnifiedLTO = CodeGenOpts.UnifiedLTO;
+  PTO.UnifiedLTO = CodeGenOpts.UnifiedLTO || CodeGenOpts.FatLTO;
----------------
teresajohnson wrote:

Ah ok. I guess that would be expected. Whether it is test friendly is another question, but in general the driver does a lot of option set up for the cc1 invocation.

https://github.com/llvm/llvm-project/pull/72180