Vector ICs: gyp flag to run with vector-stores on.

tools/gyp/v8.gyp

Index: tools/gyp/v8.gyp
diff --git a/tools/gyp/v8.gyp b/tools/gyp/v8.gyp
index a64851a3ed9bcfb1051d7e4e947e65c85bb9ae36..a5b6e055cf70e5ae353e5ae6ec9760af4cd8ff0f 100644
--- a/tools/gyp/v8.gyp
+++ b/tools/gyp/v8.gyp
@@ -30,6 +30,7 @@
     'icu_use_data_file_flag%': 0,
     'v8_code': 1,
     'v8_random_seed%': 314159265,
+    'v8_vector_stores%': 0,
     'embed_script%': "",
     'v8_extra_library_files%': [],
     'v8_experimental_extra_library_files%': [],
@@ -205,6 +206,9 @@
               ['v8_random_seed!=0', {
                 'mksnapshot_flags': ['--random-seed', '<(v8_random_seed)'],
               }],
+              ['v8_vector_stores!=0', {
+                'mksnapshot_flags': ['--vector-stores'],
+              }],
             ],
           },
           'action': [
@@ -307,6 +311,9 @@
                   ['v8_random_seed!=0', {
                     'mksnapshot_flags': ['--random-seed', '<(v8_random_seed)'],
                   }],
+                  ['v8_vector_stores!=0', {
+                    'mksnapshot_flags': ['--vector-stores'],
+                  }],
                 ],
               },
               'conditions': [