[date] Refactor the %_DateField intrinsic to be optimizable.

src/hydrogen-instructions.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/base/bits.h"
 #include "src/double.h"
 #include "src/factory.h"
 #include "src/hydrogen-infer-representation.h"
@@ skipping 1608 matching lines @@
                                           InstanceType* last) {
   DCHECK(is_interval_check());
   switch (check_) {
     case IS_SPEC_OBJECT:
       *first = FIRST_SPEC_OBJECT_TYPE;
       *last = LAST_SPEC_OBJECT_TYPE;
       return;
     case IS_JS_ARRAY:
       *first = *last = JS_ARRAY_TYPE;
       return;
+    case IS_JS_DATE:
+      *first = *last = JS_DATE_TYPE;
+      return;
     default:
       UNREACHABLE();
   }
 }
 
 
 void HCheckInstanceType::GetCheckMaskAndTag(uint8_t* mask, uint8_t* tag) {
   DCHECK(!is_interval_check());
   switch (check_) {
     case IS_STRING:
@@ skipping 49 matching lines @@
 HValue* HCheckValue::Canonicalize() {
   return (value()->IsConstant() &&
           HConstant::cast(value())->EqualsUnique(object_)) ? NULL : this;
 }
 
 
 const char* HCheckInstanceType::GetCheckName() const {
   switch (check_) {
     case IS_SPEC_OBJECT: return "object";
     case IS_JS_ARRAY: return "array";
+    case IS_JS_DATE:
+      return "date";
     case IS_STRING: return "string";
     case IS_INTERNALIZED_STRING: return "internalized_string";
   }
   UNREACHABLE();
   return "";
 }
 
 
 std::ostream& HCheckInstanceType::PrintDataTo(
     std::ostream& os) const {  // NOLINT
@@ skipping 3001 matching lines @@
     case HObjectAccess::kExternalMemory:
       os << "[external-memory]";
       break;
   }
 
   return os << "@" << access.offset();
 }
 
 }  // namespace internal
 }  // namespace v8