Optionally export metadata with libv8 to enable debuggers to inspect V8 state.

tools/gyp/v8.gyp

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 711 matching lines @@
               'link_settings':  {
                 'libraries': [ '-lwinmm.lib', '-lws2_32.lib' ],
               },
             }],
             ['component=="shared_library"', {
               'defines': [
                 'BUILDING_V8_SHARED',
                 'V8_SHARED',
               ],
             }],
+            ['v8_postmortem_support=="true"', {
+              'sources': [
+                '<(SHARED_INTERMEDIATE_DIR)/debug-support.cc',
+              ]
+            }],
           ],
         },
         {
           'target_name': 'js2c',
           'type': 'none',
           'conditions': [
             ['want_separate_host_toolset==1', {
               'toolsets': ['host'],
             }, {
               'toolsets': ['target'],
@@ skipping 56 matching lines @@
                 '../../tools/js2c.py',
                 '<@(_outputs)',
                 'EXPERIMENTAL',
                 '<(v8_compress_startup_data)',
                 '<@(experimental_library_files)'
               ],
             },
           ],
         },
         {
+          'target_name': 'postmortem-metadata',
+          'type': 'none',
+          'variables': {
+            'heapobject_files': [
+                '../../src/objects.h',
+                '../../src/objects-inl.h',
+            ],
+          },
+          'actions': [
+              {
+                'action_name': 'gen-postmortem-metadata',
+                'inputs': [
+                  '../../tools/gen-postmortem-metadata.py',
+                  '<@(heapobject_files)',
+                ],
+                'outputs': [
+                  '<(SHARED_INTERMEDIATE_DIR)/debug-support.cc',
+                ],
+                'action': [
+                  'python',
+                  '../../tools/gen-postmortem-metadata.py',
+                  '<@(_outputs)',
+                  '<@(heapobject_files)'
+                ]
+              }
+           ]
+        },
+        {
           'target_name': 'mksnapshot',
           'type': 'executable',
           'dependencies': [
             'v8_base',
             'v8_nosnapshot',
           ],
           'include_dirs+': [
             '../../src',
           ],
           'sources': [
@@ skipping 132 matching lines @@
             }],
           ],
           'dependencies': [
             'v8'
           ],
         },
       ],
     }],
   ],
 }