Define CAN_USE_VFP2/3_INSTRUCTIONS based on arm_neon and arm_fpu flags.

build/common.gypi

 # 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 125 matching lines @@
           [ 'v8_can_use_unaligned_accesses=="true"', {
             'defines': [
               'CAN_USE_UNALIGNED_ACCESSES=1',
             ],
           }],
           [ 'v8_can_use_unaligned_accesses=="false"', {
             'defines': [
               'CAN_USE_UNALIGNED_ACCESSES=0',
             ],
           }],
-          [ 'v8_can_use_vfp2_instructions=="true"', {
+          # NEON implies VFP3 and VFP3 implies VFP2.
+          [ 'v8_can_use_vfp2_instructions=="true" or arm_neon==1 or \
+             arm_fpu=="vfpv3" or arm_fpu=="vfpv3-d16"', {
             'defines': [
               'CAN_USE_VFP2_INSTRUCTIONS',
             ],
           }],
-          [ 'v8_can_use_vfp3_instructions=="true"', {
+          # NEON implies VFP3.
+          [ 'v8_can_use_vfp3_instructions=="true" or arm_neon==1 or \
+             arm_fpu=="vfpv3" or arm_fpu=="vfpv3-d16"', {
             'defines': [
               'CAN_USE_VFP3_INSTRUCTIONS',
             ],
           }],
           [ 'v8_use_arm_eabi_hardfloat=="true"', {
             'defines': [
               'USE_EABI_HARDFLOAT=1',
               'CAN_USE_VFP3_INSTRUCTIONS',
             ],
             'target_conditions': [
@@ skipping 287 matching lines @@
                 'OptimizeReferences': '2',
                 'EnableCOMDATFolding': '2',
               },
             },
           }],  # OS=="win"
         ],  # conditions
       },  # Release
     },  # configurations
   },  # target_defaults
 }