Auto-generate v8 version based on tags.

tools/gyp/v8.gyp

Index: tools/gyp/v8.gyp
diff --git a/tools/gyp/v8.gyp b/tools/gyp/v8.gyp
index 696434daf8a6ced0e6f6937453808079f43740eb..bceda29d10b1d8ffa8a5d55e5ce0796eac99b627 100644
--- a/tools/gyp/v8.gyp
+++ b/tools/gyp/v8.gyp
@@ -329,10 +329,32 @@
       ],
     },
     {
+      'target_name': 'v8_version',
+      'type': 'none',
+      'actions': [
+        {
+          'action_name': 'generate_v8_version',
+          'inputs': [
+            '../../tools/push-to-trunk/generate_version.py',
+            '../../src/version.cc',
+          ],
+          'outputs': [
+            '<(SHARED_INTERMEDIATE_DIR)/version.cc',
+          ],
+          'action': [
+            'python',
+            '../../tools/push-to-trunk/generate_version.py',
+            '<(SHARED_INTERMEDIATE_DIR)/version.cc',
+          ],
+        },
+      ],
+    },
+    {
       'target_name': 'v8_base',
       'type': 'static_library',
       'dependencies': [
         'v8_libbase',
+        'v8_version',
       ],
       'variables': {
         'optimize': 'max',
@@ -875,7 +897,7 @@
         '../../src/variables.cc',
         '../../src/variables.h',
         '../../src/vector.h',
-        '../../src/version.cc',
+        '<(SHARED_INTERMEDIATE_DIR)/version.cc',
         '../../src/version.h',
         '../../src/vm-state-inl.h',
         '../../src/vm-state.h',