[llvm] [llvm-profgen] Filter out ambiguous cold profiles during profile generation (PR #81803)

[via llvm-commits]

================
@@ -492,6 +525,7 @@ void ProfileGenerator::postProcessProfiles() {
   computeSummaryAndThreshold(ProfileMap);
   trimColdProfiles(ProfileMap, ColdCountThreshold);
   calculateAndShowDensity(ProfileMap);
+  filterAmbiguousProfile(ProfileMap);
----------------
WenleiHe wrote:

nit: move this to be right after trimming, filter is also one form of trimming, and we should do that together before calculating stats/density. 

https://github.com/llvm/llvm-project/pull/81803