Add yasm flags for 64-bit mac builds

third_party/yasm/yasm_compile.gypi

 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # This is an gyp include to use YASM for compiling assembly files.
 #
 # Files to be compiled with YASM should have an extension of .asm.
 #
 # There are two variables for this include:
 # yasm_flags : Pass additional flags into YASM.
@@ skipping 37 matching lines @@
           '-felf64',
           '-m', 'amd64',
         ],
       }],
       [ 'OS=="mac" and target_arch=="ia32"', {
         'yasm_flags': [
           '-fmacho32',
           '-m', 'x86',
         ],
       }],
+      [ 'OS=="mac" and target_arch=="x64"', {
+        'yasm_flags': [
+          '-fmacho64',
+          '-m', 'amd64', # yasm uses 'amd64' as flag for the 64-bit instruction set.

[Mark Mentovai, 2012/09/19 13:50:53]

80 characters.

I actually don’t think the comment is necessary at all.

+        ],
+      }],
       [ 'OS=="win" and target_arch=="ia32"', {
         'yasm_flags': [
           '-DPREFIX',
           '-fwin32',
           '-m', 'x86',
         ],
       }],
 
       # Define output extension.
       ['OS=="win"', {
@@ skipping 26 matching lines @@
         '<(yasm_path)',
         '<@(yasm_flags)',
         '-o', '<(yasm_output_path)/<(RULE_INPUT_ROOT).<(asm_obj_extension)',
         '<(RULE_INPUT_PATH)',
       ],
       'process_outputs_as_sources': 1,
       'message': 'Compile assembly <(RULE_INPUT_PATH).',
     },
   ],  # rules
 }