Allow embedder to set promise internal field count

gypfiles/features.gypi

 # Copyright 2013 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 13 matching lines @@
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 # Compile time controlled V8 features.
 
 {
   'variables': {
     'v8_enable_disassembler%': 0,
 
+    'v8_promise_internal_field_count%': 0,
+
     'v8_enable_gdbjit%': 0,
 
     'v8_enable_verify_csa%': 0,
 
     'v8_object_print%': 0,
 
     'v8_enable_verify_heap%': 0,
 
     'v8_trace_maps%': 0,
 
@@ skipping 26 matching lines @@
     'dcheck_always_on%': 0,
 
     # Enable/disable JavaScript API accessors.
     'v8_js_accessors%': 0,
   },
   'target_defaults': {
     'conditions': [
       ['v8_enable_disassembler==1', {
         'defines': ['ENABLE_DISASSEMBLER',],
       }],
+      ['v8_promise_internal_field_count!=0', {
+        'defines': ['V8_PROMISE_INTERNAL_FIELD_COUNT','v8_promise_internal_field_count'],
+      }],
       ['v8_enable_gdbjit==1', {
         'defines': ['ENABLE_GDB_JIT_INTERFACE',],
       }],
       ['v8_enable_verify_csa==1', {
         'defines': ['ENABLE_VERIFY_CSA',],
       }],
       ['v8_object_print==1', {
         'defines': ['OBJECT_PRINT',],
       }],
       ['v8_enable_verify_heap==1', {
@@ skipping 45 matching lines @@
             'defines': ['ENABLE_HANDLE_ZAPPING',],
           }],
         ],  # conditions
       },  # Release
     },  # configurations
     'defines': [
       'V8_GYP_BUILD',
     ],  # defines
   },  # target_defaults
 }