[llvm] [HWASAN] Follow up for #83503 implement selective instrumentation (PR #83942)

[Vitaly Buka via llvm-commits]

================
@@ -1526,19 +1534,28 @@ void HWAddressSanitizer::sanitizeFunction(Function &F,
     return;
 
   NumTotalFuncs++;
-  if (CSkipHotCode) {
-    auto &MAMProxy = FAM.getResult<ModuleAnalysisManagerFunctionProxy>(F);
-    ProfileSummaryInfo *PSI =
-        MAMProxy.getCachedResult<ProfileSummaryAnalysis>(*F.getParent());
-    if (PSI && PSI->hasProfileSummary()) {
-      auto &BFI = FAM.getResult<BlockFrequencyAnalysis>(F);
-      if ((HotPercentileCutoff.getNumOccurrences() && HotPercentileCutoff >= 0)
-              ? PSI->isFunctionHotInCallGraphNthPercentile(HotPercentileCutoff,
-                                                           &F, BFI)
-              : PSI->isFunctionHotInCallGraph(&F, BFI))
-        return;
+  if (CSelectiveInstrumentation) {
+    if (RandomSkipRate.getNumOccurrences()) {
+      std::unique_ptr<RandomNumberGenerator> Rng = F.getParent()->createRNG(F.getName());
----------------
vitalybuka wrote:

'remove-traps-random-rate" is function pass, so I need to recreate random every function

HWAddressSanitizer is module pass, so you can make it the class member.
```
HWAddressSanitizer(Module &M, bool CompileKernel, bool Recover,
                     const StackSafetyGlobalInfo *SSI) : Rng(M->createRNG("hwasan"))
```

Note module name is already appended in createRNG

https://github.com/llvm/llvm-project/pull/83942