[InstCombine] Rename some shadow variables; NFC

[RKSimon]

LGTM

[goldstein.w.n]

Rebase

llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp

if (match(&I, m_And(m_OneUse(m_Shl(m_ZExt(m_Value(X)), m_Value(Y))),
     return BinaryOperator::CreateAnd(SExt, SanitizedSignMask);
   }
 
   if (Instruction *Z = narrowMaskedBinOp(I))
     return Z;
 
   if (I.getType()->isIntOrIntVectorTy(1)) {
     if (auto *SI0 = dyn_cast<SelectInst>(Op0)) {
-      if (auto *I =
+      if (auto *R =
               foldAndOrOfSelectUsingImpliedCond(Op1, *SI0, /* IsAnd */ true))
-        return I;
+        return R;
     }
     if (auto *SI1 = dyn_cast<SelectInst>(Op1)) {
-      if (auto *I =
+      if (auto *R =
               foldAndOrOfSelectUsingImpliedCond(Op0, *SI1, /* IsAnd */ true))
-        return I;
+        return R;
     }
   }
 
   if (Instruction *FoldedLogic = foldBinOpIntoSelectOrPhi(I))
     return FoldedLogic;
 
   if (Instruction *DeMorgan = matchDeMorgansLaws(I, Builder))
     return DeMorgan;
Instruction *InstCombinerImpl::visitOr(BinaryOperator &I) {
 
   if (Value *V = SimplifyBSwap(I, Builder))
     return replaceInstUsesWith(I, V);
 
   Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
   Type *Ty = I.getType();
   if (Ty->isIntOrIntVectorTy(1)) {
     if (auto *SI0 = dyn_cast<SelectInst>(Op0)) {
-      if (auto *I =
+      if (auto *R =
               foldAndOrOfSelectUsingImpliedCond(Op1, *SI0, /* IsAnd */ false))
-        return I;
+        return R;
     }
     if (auto *SI1 = dyn_cast<SelectInst>(Op1)) {
-      if (auto *I =
+      if (auto *R =
               foldAndOrOfSelectUsingImpliedCond(Op0, *SI1, /* IsAnd */ false))
-        return I;
+        return R;
     }
   }
 
   if (Instruction *FoldedLogic = foldBinOpIntoSelectOrPhi(I))
     return FoldedLogic;
 
   if (Instruction *BitOp = matchBSwapOrBitReverse(I, /*MatchBSwaps*/ true,
                                                   /*MatchBitReversals*/ true))