[coverage] Use optimized builds for coverage data.

build/standalone.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 716 matching lines @@
           [ 'host_arch=="ppc64" and OS!="aix"', {
             'cflags': [ '-mminimal-toc' ],
           }],
           [ 'visibility=="hidden" and v8_enable_backtrace==0', {
             'cflags': [ '-fvisibility=hidden' ],
           }],
           [ 'component=="shared_library"', {
             'cflags': [ '-fPIC', ],
           }],
           [ 'coverage==1', {
-            'cflags!': [ '-O3', '-O2', '-O1', ],
-            'cflags': [ '-fprofile-arcs', '-ftest-coverage', '-O0'],
+            'cflags': [ '-fprofile-arcs', '-ftest-coverage'],
             'ldflags': [ '-fprofile-arcs'],
           }],
         ],
       },
     }],
     # 'OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="solaris"
     #  or OS=="netbsd"'
     ['OS=="qnx"', {
       'target_defaults': {
         'cflags': [
@@ skipping 618 matching lines @@
               '-fsanitize=cfi-vcall',
               '-fsanitize=cfi-derived-cast',
               '-fsanitize=cfi-unrelated-cast',
             ],
           }],
         ],
       },
     }],
   ],
 }