[llvm] [Pass] Support start/stop in instrumentation (PR #70912)

[via llvm-commits]

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@@ -28,6 +28,14 @@ PassInstrumentationCallbacks::getPassNameForClassName(StringRef ClassName) {
   return ClassToPassName[ClassName];
 }
 
+StringRef
+PassInstrumentationCallbacks::getClassNameForPassName(StringRef PassName) {
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paperchalice wrote:

Then we may need #76320 to populate pass names.

https://github.com/llvm/llvm-project/pull/70912