[clang] [llvm] Compute GUIDs once and store in metadata (PR #184065)

[Teresa Johnson via cfe-commits]

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@@ -527,14 +528,21 @@ bool llvm::runPassPipeline(
   case OK_NoOutput:
     break; // No output pass needed.
   case OK_OutputAssembly:
+    if (EmitSummaryIndex) {
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teresajohnson wrote:

Can you add a comment that this is for pre-existing tests that don't have the GUID metadata? To avoid duplication you could also pull all 3 calls out of the switch with one comment. For simplicity I don't even think you need to make it conditional, as this is for tests. But if you do make it conditional here or pulled up, no braces for single line if bodies.

https://github.com/llvm/llvm-project/pull/184065