Revert of Remove SIMD.js from V8.

src/type-hints.h

 // Copyright 2015 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.
 
 #ifndef V8_TYPE_HINTS_H_
 #define V8_TYPE_HINTS_H_
 
 #include "src/base/flags.h"
 #include "src/utils.h"
 
@@ skipping 38 matching lines @@
 enum class ToBooleanHint : uint16_t {
   kNone = 0u,
   kUndefined = 1u << 0,
   kBoolean = 1u << 1,
   kNull = 1u << 2,
   kSmallInteger = 1u << 3,
   kReceiver = 1u << 4,
   kString = 1u << 5,
   kSymbol = 1u << 6,
   kHeapNumber = 1u << 7,
+  kSimdValue = 1u << 8,
   kAny = kUndefined | kBoolean | kNull | kSmallInteger | kReceiver | kString |
-         kSymbol | kHeapNumber,
-  kNeedsMap = kReceiver | kString | kSymbol | kHeapNumber,
+         kSymbol | kHeapNumber | kSimdValue,
+  kNeedsMap = kReceiver | kString | kSymbol | kHeapNumber | kSimdValue,
   kCanBeUndetectable = kReceiver,
 };
 
 std::ostream& operator<<(std::ostream&, ToBooleanHint);
 std::string ToString(ToBooleanHint);
 
 typedef base::Flags<ToBooleanHint, uint16_t> ToBooleanHints;
 
 std::ostream& operator<<(std::ostream&, ToBooleanHints);
 std::string ToString(ToBooleanHints);
@@ skipping 14 matching lines @@
   STRING_ADD_CONVERT_LEFT = STRING_ADD_CHECK_LEFT | STRING_ADD_CONVERT,
   STRING_ADD_CONVERT_RIGHT = STRING_ADD_CHECK_RIGHT | STRING_ADD_CONVERT
 };
 
 std::ostream& operator<<(std::ostream& os, const StringAddFlags& flags);
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TYPE_HINTS_H_