[SSAUpdater] Don't call ValueIsRAUWd upon single use replacement

[DaniilSuchkov]

Summary

It is incorrect to call ValueHandleBase::ValueIsRAUWd when only one use is replaced since it simply violates semantics of the callback and leads to bugs like this one: https://bugs.llvm.org/show_bug.cgi?id=44320
Previously this call was used specifically to keep LICM's cache of AliasSetTrackers up to date across passes (as the bug #36801 showed, even for that purpose it didn't work properly), but since LICM doesn't have that cache anymore (as of D73084), we can safely remove this incorrect call with no repercussions.

This patch fixes https://bugs.llvm.org/show_bug.cgi?id=44320

[asbirlea]

LGTM.

llvm/lib/Transforms/Utils/SSAUpdater.cpp

void SSAUpdater::RewriteUse(Use &U) {
   Instruction *User = cast<Instruction>(U.getUser());
 
   Value *V;
   if (PHINode *UserPN = dyn_cast<PHINode>(User))
     V = GetValueAtEndOfBlock(UserPN->getIncomingBlock(U));
   else
     V = GetValueInMiddleOfBlock(User->getParent());
 
-  // Notify that users of the existing value that it is being replaced.
-  Value *OldVal = U.get();
-  if (OldVal != V && OldVal->hasValueHandle())
-    ValueHandleBase::ValueIsRAUWd(OldVal, V);
-
   U.set(V);
 }
 
 void SSAUpdater::RewriteUseAfterInsertions(Use &U) {
   Instruction *User = cast<Instruction>(U.getUser());
 
   Value *V;
   if (PHINode *UserPN = dyn_cast<PHINode>(User))

llvm/test/Transforms/LCSSA/pr44320.ll

-; XFAIL: *
 ; RUN: opt -passes="verify<scalar-evolution>,lcssa,verify<scalar-evolution>" -verify-scev-strict -S -disable-output %s
 
 ; The first SCEV verification is required because it queries SCEV and populates
 ; SCEV caches. Second SCEV verification checks if the caches are in valid state.
 
 ; Check that the second SCEV verification doesn't fail.
 define void @test(i32* %arg, i32* %arg1, i1 %arg2, i1 %arg3) {
 bb: