Add GN target for the sample shell

I want to stop using d8 from the chromium build, so we could potentially
use it for running tests.

BUG=chromium:609107
R=machenbach@chromium.org
LOG=n

Review-Url: https://codereview.chromium.org/1944353002
Cr-Commit-Position: refs/heads/master@{#36060}

BUILD.gn

@@ -65,6 +65,7 @@ declare_args() {
 
 v8_random_seed = "314159265"
 v8_toolset_for_d8 = "host"
+v8_toolset_for_shell = "host"
 
 if (is_msan) {
   # Running the V8-generated code on an ARM simulator is a powerful hack that
@@ -2127,6 +2128,38 @@ if ((current_toolchain == host_toolchain && v8_toolset_for_d8 == "host") ||
   }
 }
 
+if ((current_toolchain == host_toolchain && v8_toolset_for_shell == "host") ||
+    (current_toolchain == snapshot_toolchain && v8_toolset_for_shell == "host") ||
+    (current_toolchain != host_toolchain && v8_toolset_for_shell == "target")) {
+  executable("shell") {
+    sources = [
+      "samples/shell.cc",
+    ]
+
+    configs -= [ "//build/config/compiler:chromium_code" ]
+    configs += [ "//build/config/compiler:no_chromium_code" ]
+    configs += [
+      # Note: don't use :internal_config here because this target will get
+      # the :external_config applied to it by virtue of depending on :v8, and
+      # you can't have both applied to the same target.
+      ":internal_config_base",
+      ":features",
+      ":toolchain",
+    ]
+
+    deps = [
+      ":v8",
+      ":v8_libplatform",
+      "//build/config/sanitizers:deps",
+      "//build/win:default_exe_manifest",
+    ]
+
+    if (v8_enable_i18n_support) {
+      deps += [ "//third_party/icu" ]
+    }
+  }
+}
+
 source_set("json_fuzzer") {
   sources = [
     "test/fuzzer/json.cc",

gypfiles/toolchain.gypi

@@ -81,6 +81,11 @@
     # The setting is ignored if want_separate_host_toolset is 0.
     'v8_toolset_for_d8%': 'target',
 
+    # Toolset the shell binary should be compiled for. Possible values are
+    # 'host' and 'target'.
+    # The setting is ignored if want_separate_host_toolset is 0.
+    'v8_toolset_for_shell%': 'target',
+
     'host_os%': '<(OS)',
     'werror%': '-Werror',
     # For a shared library build, results in "libv8-<(soname_version).so".

samples/samples.gyp

@@ -29,6 +29,7 @@
   'variables': {
     'v8_code': 1,
     'v8_enable_i18n_support%': 1,
+    'v8_toolset_for_shell%': 'target',
   },
   'includes': ['../gypfiles/toolchain.gypi', '../gypfiles/features.gypi'],
   'target_defaults': {
@@ -60,6 +61,11 @@
       'sources': [
         'shell.cc',
       ],
+      'conditions': [
+        [ 'want_separate_host_toolset==1', {
+          'toolsets': [ '<(v8_toolset_for_shell)', ],
+        }],
+      ],
     },
     {
       'target_name': 'hello-world',