Put V8 extras into the snapshot

src/snapshot/serialize.h

 // 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.
 
 #ifndef V8_SNAPSHOT_SERIALIZE_H_
 #define V8_SNAPSHOT_SERIALIZE_H_
 
 #include "src/hashmap.h"
 #include "src/isolate.h"
 #include "src/snapshot/snapshot-source-sink.h"
@@ skipping 383 matching lines @@
   static const int kNativesStringResource = 0x37;
   // Raw data of variable length.
   static const int kVariableRawData = 0x57;
   // Repeats of variable length.
   static const int kVariableRepeat = 0x77;
   // Alignment prefixes 0x7d..0x7f
   static const int kAlignmentPrefix = 0x7d;
   // Used for the source code for compiled stubs, which is in the executable,
   // but is referred to from external strings in the snapshot.
   static const int kCodeStubNativesStringResource = 0x5d;
+  // Used for the source code for V8 extras, which is in the executable,
+  // but is referred to from external strings in the snapshot.
+  static const int kExtraNativesStringResource = 0x5e;

[Yang, 2015/08/13 12:28:24]

This is fine, but I'd group them a bit differently. Maybe 0x5d..0x5f for the
three k*StringResources, and sort it to right after kDeferred, swap
kVariableRepeat to 0x37 and leave 0x77 unused.

Not that it really matters, but it would be somewhat nicer.

 
-  // 0x5e..0x5f unused
+  // 0x5f unused
 
   // ---------- byte code range 0x80..0xff ----------
   // First 32 root array items.
   static const int kNumberOfRootArrayConstants = 0x20;
   // 0x80..0x9f
   static const int kRootArrayConstants = 0x80;
   // 0xa0..0xbf
   static const int kRootArrayConstantsWithSkip = 0xa0;
   static const int kRootArrayConstantsMask = 0x1f;
 
@@ skipping 633 matching lines @@
   static const int kNumReservationsOffset = kFlagHashOffset + kInt32Size;
   static const int kNumCodeStubKeysOffset = kNumReservationsOffset + kInt32Size;
   static const int kPayloadLengthOffset = kNumCodeStubKeysOffset + kInt32Size;
   static const int kChecksum1Offset = kPayloadLengthOffset + kInt32Size;
   static const int kChecksum2Offset = kChecksum1Offset + kInt32Size;
   static const int kHeaderSize = kChecksum2Offset + kInt32Size;
 };
 } }  // namespace v8::internal
 
 #endif  // V8_SNAPSHOT_SERIALIZE_H_