[cleanup] Use brace initialization instead of a static cast

We change a bunch of static_cast to a cleaner and shorter brace
initialization. I did not change every use of static_cast in the files,
just those that relate to SIMD, so as to not cause churn in the
diff/blame.

Change-Id: I7e90c1b81f09a1e7a3ae7c9825db4fdbd21db919
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2159737Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67373}

src/compiler/backend/ia32/code-generator-ia32.cc

@@ -498,7 +498,7 @@ class OutOfLineRecordWrite final : public OutOfLineCode {
     XMMRegister dst = i.OutputSimd128Register();       \
     DCHECK_EQ(dst, i.InputSimd128Register(0));         \
     if (HasImmediateInput(instr, 1)) {                 \
-      __ opcode(dst, dst, static_cast<byte>(i.InputInt##width(1))); \
+      __ opcode(dst, dst, byte{i.InputInt##width(1)}); \
     } else {                                           \
       XMMRegister tmp = i.TempSimd128Register(0);      \
       Register tmp_shift = i.TempRegister(1);          \
@@ -3168,7 +3168,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       if (HasImmediateInput(instr, 1)) {
         // Perform 16-bit shift, then mask away low bits.
         uint8_t shift = i.InputInt3(1);
-        __ Psllw(dst, dst, static_cast<byte>(shift));
+        __ Psllw(dst, dst, byte{shift});
 
         uint8_t bmask = static_cast<uint8_t>(0xff << shift);
         uint32_t mask = bmask << 24 | bmask << 16 | bmask << 8 | bmask;
@@ -3469,7 +3469,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       if (HasImmediateInput(instr, 1)) {
         // Perform 16-bit shift, then mask away high bits.
         uint8_t shift = i.InputInt3(1);
-        __ Psrlw(dst, dst, static_cast<byte>(shift));
+        __ Psrlw(dst, dst, byte{shift});
 
         uint8_t bmask = 0xff >> shift;
         uint32_t mask = bmask << 24 | bmask << 16 | bmask << 8 | bmask;
@@ -3715,7 +3715,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
     case kIA32S16x8LoadSplat: {
       __ Pinsrw(i.OutputSimd128Register(), i.MemoryOperand(), 0);
       __ Pshuflw(i.OutputSimd128Register(), i.OutputSimd128Register(),
-                 static_cast<uint8_t>(0));
+                 uint8_t{0});
       __ Punpcklqdq(i.OutputSimd128Register(), i.OutputSimd128Register());
       break;
     }