[CVP] Preserve exact name when converting sext->zext and ashr->lshr.

Previously we took the old name and always appended a numberic suffix.
Since we're doing a 1:1 replacement, it's clearer to keep the original
name exactly.

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D125281

llvm/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp

@@ -961,7 +961,8 @@ static bool processAShr(BinaryOperator *SDI, LazyValueInfo *LVI) {
 
   ++NumAShrsConverted;
   auto *BO = BinaryOperator::CreateLShr(SDI->getOperand(0), SDI->getOperand(1),
-                                        SDI->getName(), SDI);
+                                        "", SDI);
+  BO->takeName(SDI);
   BO->setDebugLoc(SDI->getDebugLoc());
   BO->setIsExact(SDI->isExact());
   SDI->replaceAllUsesWith(BO);
@@ -980,8 +981,8 @@ static bool processSExt(SExtInst *SDI, LazyValueInfo *LVI) {
     return false;
 
   ++NumSExt;
-  auto *ZExt =
-      CastInst::CreateZExtOrBitCast(Base, SDI->getType(), SDI->getName(), SDI);
+  auto *ZExt = CastInst::CreateZExtOrBitCast(Base, SDI->getType(), "", SDI);
+  ZExt->takeName(SDI);
   ZExt->setDebugLoc(SDI->getDebugLoc());
   SDI->replaceAllUsesWith(ZExt);
   SDI->eraseFromParent();