[X86] Fix parentheses for clarity in X86ISelLowering.cpp (llvm#121954)

fixes llvm#121908

This pull request resolves issue llvm#121908 by adding proper parentheses in
X86ISelLowering.cpp to follow operator precedence rules. This change
ensures better code clarity and avoids ambiguity.

Author: soumyaGhoshh

llvm/lib/Target/X86/X86ISelLowering.cpp

@@ -42431,7 +42431,7 @@ static SDValue combineTargetShuffle(SDValue N, const SDLoc &DL,
       // Canonicalize to VPERMV if both sources are the same.
       if (V1 == V2) {
         for (int &M : Mask)
-          M = (M < 0 ? M : M & Mask.size() - 1);
+          M = (M < 0 ? M : M & (Mask.size() - 1));
         SDValue NewMask = getConstVector(Mask, MaskVT, DAG, DL,
                                          /*IsMask=*/true);
         return DAG.getNode(X86ISD::VPERMV, DL, VT, NewMask, N.getOperand(0));