Enable UMOD optimization for x64 (#68091)

Author: TIHan

src/coreclr/jit/morph.cpp

@@ -10759,14 +10759,14 @@ GenTree* Compiler::fgMorphSmpOp(GenTree* tree, MorphAddrContext* mac)
 
             if (!optValnumCSE_phase)
             {
-#ifdef TARGET_ARM64
                 if (tree->OperIs(GT_UMOD) && op2->IsIntegralConstUnsignedPow2())
                 {
                     // Transformation: a % b = a & (b - 1);
                     tree = fgMorphUModToAndSub(tree->AsOp());
                     op1  = tree->AsOp()->gtOp1;
                     op2  = tree->AsOp()->gtOp2;
                 }
+#ifdef TARGET_ARM64
                 // ARM64 architecture manual suggests this transformation
                 // for the mod operator.
                 // However, we do skip this optimization for ARM64 if the second operand
@@ -10779,7 +10779,7 @@ GenTree* Compiler::fgMorphSmpOp(GenTree* tree, MorphAddrContext* mac)
                 // when 'b' is not a power of 2 constant and mod operator is signed.
                 // Lowering for XARCH does this optimization already,
                 // but is also done here to take advantage of CSE.
-                if (tree->OperIs(GT_MOD) && op2->IsIntegralConst() && !op2->IsIntegralConstAbsPow2())
+                else if (tree->OperIs(GT_MOD) && op2->IsIntegralConst() && !op2->IsIntegralConstAbsPow2())
 #endif
                 {
                     // Transformation: a % b = a - (a / b) * b;