Tentatively merge llvm fix for buildworld WITH_ASAN

Building world using WITH_ASAN results in an assertion when compiling
certain source files referencing ifuncs:

  Assertion failed: (isa<Function>(Callee) || isa<GlobalAlias>(Callee)), function analyzeAllUses, file /root/freebsd/contrib/llvm-project/llvm/lib/Analysis/StackSafetyAnalysis.cpp, line 514.

This was already reported upstream a while ago, in
<llvm/llvm-project#87923>, but now there is
finally a candidate fix, which seems trivial so I am importing it right
away.

Reported by:	markj
PR:		280936
Pull Request:	llvm/llvm-project#113841
MFC after:	3 days

(cherry picked from commit f3457ed)

Author: DimitryAndric

contrib/llvm-project/llvm/lib/Analysis/StackSafetyAnalysis.cpp

@@ -506,7 +506,7 @@ void StackSafetyLocalAnalysis::analyzeAllUses(Value *Ptr,
         // dso_preemptable aliases or aliases with interposable linkage.
         const GlobalValue *Callee =
             dyn_cast<GlobalValue>(CB.getCalledOperand()->stripPointerCasts());
-        if (!Callee) {
+        if (!Callee || isa<GlobalIFunc>(Callee)) {
           US.addRange(I, UnknownRange, /*IsSafe=*/false);
           break;
         }