[InstrProfiling] Fix emitting runtime hook once

[gulfem]

Summary

https://reviews.llvm.org/D134254 introduced an issue on Fuchsia
target, which does not unconditionally emit runtime hook.
It used containsProfilingIntrinsics(M) after intrinsics are lowered.
So, this patch fixes the issue by capturing the result of that
function invocation before intrinsics are lowered.

[phosek]

LGTM

llvm/lib/Transforms/Instrumentation/InstrProfiling.cpp

bool InstrProfiling::run(
   UsedVars.clear();
   TT = Triple(M.getTargetTriple());
 
   bool MadeChange = false;
   bool NeedsRuntimeHook = needsRuntimeHookUnconditionally(TT);
   if (NeedsRuntimeHook)
     MadeChange = emitRuntimeHook();
 
-  // Improve compile time by avoiding linear scans when there is no work.
+  bool ContainsProfiling = containsProfilingIntrinsics(M);
   GlobalVariable *CoverageNamesVar =
       M.getNamedGlobal(getCoverageUnusedNamesVarName());
-  if (!containsProfilingIntrinsics(M) && !CoverageNamesVar)
+  // Improve compile time by avoiding linear scans when there is no work.
+  if (!ContainsProfiling && !CoverageNamesVar)
     return MadeChange;
 
   // We did not know how many value sites there would be inside
   // the instrumented function. This is counting the number of instrumented
   // target value sites to enter it as field in the profile data variable.
   for (Function &F : M) {
     InstrProfIncrementInst *FirstProfIncInst = nullptr;
     for (BasicBlock &BB : F)
bool InstrProfiling::run(
 
   emitVNodes();
   emitNameData();
 
   // Emit runtime hook for the cases where the target does not unconditionally
   // require pulling in profile runtime, and coverage is enabled on code that is
   // not eliminated by the front-end, e.g. unused functions with internal
   // linkage.
-  if (!NeedsRuntimeHook && containsProfilingIntrinsics(M))
+  if (!NeedsRuntimeHook && ContainsProfiling)
     emitRuntimeHook();
 
   emitRegistration();
   emitUses();
   emitInitialization();
   return true;
 }