Add GN target for the sample shell

samples/samples.gyp

 # 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 11 matching lines @@
 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 {
   'variables': {
     'v8_code': 1,
     'v8_enable_i18n_support%': 1,
+    'v8_toolset_for_shell%': 'target',
   },
   'includes': ['../gypfiles/toolchain.gypi', '../gypfiles/features.gypi'],
   'target_defaults': {
     'type': 'executable',
     'dependencies': [
       '../src/v8.gyp:v8',
       '../src/v8.gyp:v8_libplatform',
     ],
     'include_dirs': [
       '..',
@@ skipping 11 matching lines @@
         ],
       }],
     ],
   },
   'targets': [
     {
       'target_name': 'shell',
       'sources': [
         'shell.cc',
       ],
+      'conditions': [
+        [ 'want_separate_host_toolset==1', {
+          'toolsets': [ '<(v8_toolset_for_shell)', ],
+        }],
+      ],
     },
     {
       'target_name': 'hello-world',
       'sources': [
         'hello-world.cc',
       ],
     },
     {
       'target_name': 'process',
       'sources': [
         'process.cc',
       ],
     },
   ],
 }