[V8] Rename SIMD Create methods and add initialization operators.

src/compiler/x64/code-generator-x64.cc

Index: src/compiler/x64/code-generator-x64.cc
diff --git a/src/compiler/x64/code-generator-x64.cc b/src/compiler/x64/code-generator-x64.cc
index c4ff4f1f7f67b579a95f417731bab3d9160d1f0b..d3f0c8877a80e3c7283e0622f2166caa40e3a704 100644
--- a/src/compiler/x64/code-generator-x64.cc
+++ b/src/compiler/x64/code-generator-x64.cc
@@ -2153,7 +2153,7 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ xchgl(i.InputRegister(index), operand);
       break;
     }
-    case kX64Int32x4Create: {
+    case kX64Int32x4Splat: {
       CpuFeatureScope sse_scope(masm(), SSE4_1);
       XMMRegister dst = i.OutputSimd128Register();
       __ Movd(dst, i.InputRegister(0));
@@ -2185,6 +2185,12 @@ CodeGenerator::CodeGenResult CodeGenerator::AssembleArchInstruction(
       __ psubd(i.OutputSimd128Register(), i.InputSimd128Register(1));
       break;
     }
+    case kX64Simd128Zero: {
+      CpuFeatureScope sse_scope(masm(), SSE4_1);
+      XMMRegister dst = i.OutputSimd128Register();
+      __ xorps(dst, dst);
+      break;
+    }
     case kCheckedLoadInt8:
       ASSEMBLE_CHECKED_LOAD_INTEGER(movsxbl);
       break;