More optimizations in debug build, makes checked mode > 3x faster.

tools/gyp/configurations_make.gypi

 # Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 {
   'variables': {
     'arm_cross_libc%': '/opt/codesourcery/arm-2009q1/arm-none-linux-gnueabi/libc',
   },
   'target_defaults': {
     'configurations': {
       'Dart_Base': {
         'cflags': [
           '-Werror',
           '<@(common_gcc_warning_flags)',
           '-Wnon-virtual-dtor',
           '-Wvla',
           # TODO(v8-team): Fix V8 build.
           #'-Woverloaded-virtual',
-          '-g',
+          '-g3',
+          '-ggdb3',
           '-ansi',
           '-fno-rtti',
           '-fno-exceptions',
           '-fPIC',
           '-fvisibility=hidden',
           '-fvisibility-inlines-hidden',
         ],
         'ldflags': [
           '-rdynamic',
           '-Wl,-rpath,<(PRODUCT_DIR)/lib.target',
@@ skipping 21 matching lines @@
           '-mfpu=vfp',
           '-mfloat-abi=softfp',
           '-fno-strict-overflow',
         ],
         'ldflags': [
           '-Wl,-rpath=<(arm_cross_libc)/usr/lib',
         ],
       },
 
       'Dart_Debug': {
-        'cflags': [ '-O0', ],
+        'cflags': [ '-O2' ],
       },
 
       'Dart_Release': {
         'cflags': [ '-O3', ],
       },
     },
   },
 }