Remove Gay's dtoa from sources.

tools/gyp/v8.gyp

Index: tools/gyp/v8.gyp
diff --git a/tools/gyp/v8.gyp b/tools/gyp/v8.gyp
index 30b15a97373630bef4122d05c0ffcbebecf253a8..43e1bd415059980790aede3c742cdfb11ed1d523 100644
--- a/tools/gyp/v8.gyp
+++ b/tools/gyp/v8.gyp
@@ -333,7 +333,6 @@
         '../../src/disassembler.h',
         '../../src/dtoa.cc',
         '../../src/dtoa.h',
-        '../../src/dtoa-config.c',
         '../../src/diy-fp.cc',
         '../../src/diy-fp.h',
         '../../src/double.h',
@@ -657,11 +656,7 @@
             '../../src/platform-win32.cc',
           ],
           # 4355, 4800 came from common.vsprops
-          # 4018, 4244 were a per file config on dtoa-config.c
-          # TODO: It's probably possible and desirable to stop disabling the
-          # dtoa-specific warnings by modifying dtoa as was done in Chromium
-          # r9255.  Refer to that revision for details.
-          'msvs_disabled_warnings': [4355, 4800, 4018, 4244],
+          'msvs_disabled_warnings': [4355, 4800],
           'link_settings':  {
             'libraries': [ '-lwinmm.lib' ],
           },