[MemProf] Context disambiguation cloning pass [patch 4/4]

[tejohnson]

Summary

Applies ThinLTO cloning decisions made during the thin link and
recorded in the summary index to the IR during the ThinLTO backend.

Depends on D141077.

[tejohnson]

Remove an extra set of identical test invocations left in by a merge.

[snehasish]

lgtm

llvm/lib/Transforms/IPO/MemProfContextDisambiguation.cpp

3091

ore::NV instead to make it clear? (similar comment in D141077)

3154

nit: The Changed temporary var can be dropped here and below too.

if (ImportSummary) 
  return applyImport(M);

3171

The documentation discourages use of ExitOrError in libraries. Though I did see some uses in places which are not tools. You could add a static create method to raise the error outside the constructor but I'm not sure whats the convention of raising a fatal error from the Module pass.

[1] https://github.com/llvm/llvm-project/blob/main/llvm/include/llvm/Support/Error.h#L1353

[tejohnson]

llvm/lib/Transforms/IPO/MemProfContextDisambiguation.cpp

3091

Done here and elsewhere with the NV calls added in this patch.

3171

Good catch. I had copied this approach from the WPD code which I guess is using the wrong mechanism, but I switched to using the mechanism used by FunctionImport.cpp which instead utilizes logAllUnhandledErrors. Also modified the control flow in this file to use early returns which I think makes it simpler to follow.

[tejohnson]

Address comments

[tejohnson]

Rebase