[NFC] Fix missplaced comment

Author: andjo403

llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp

@@ -4738,10 +4738,6 @@ Instruction *InstCombinerImpl::visitXor(BinaryOperator &I) {
   if (Instruction *R = foldBinOpShiftWithShift(I))
     return R;
 
-  // Fold (X & M) ^ (Y & ~M) -> (X & M) | (Y & ~M)
-  // This it a special case in haveNoCommonBitsSet, but the computeKnownBits
-  // calls in there are unnecessary as SimplifyDemandedInstructionBits should
-  // have already taken care of those cases.
   Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
   Value *X, *Y, *M;
 
@@ -4756,6 +4752,10 @@ Instruction *InstCombinerImpl::visitXor(BinaryOperator &I) {
       return BinaryOperator::CreateXor(XorBC, X);
   }
 
+  // Fold (X & M) ^ (Y & ~M) -> (X & M) | (Y & ~M)
+  // This it a special case in haveNoCommonBitsSet, but the computeKnownBits
+  // calls in there are unnecessary as SimplifyDemandedInstructionBits should
+  // have already taken care of those cases.
   if (match(&I, m_c_Xor(m_c_And(m_Not(m_Value(M)), m_Value()),
                         m_c_And(m_Deferred(M), m_Value())))) {
     if (isGuaranteedNotToBeUndef(M))