Fix and simplify unbundled v8.gyp:

build/linux/unbundle/v8.gyp

Index: build/linux/unbundle/v8.gyp
diff --git a/build/linux/unbundle/v8.gyp b/build/linux/unbundle/v8.gyp
index dce1a16d80c0e1178086df4315a5e874a512ad42..f7448febf8cebef530d549e65762a8f44f8eec9c 100644
--- a/build/linux/unbundle/v8.gyp
+++ b/build/linux/unbundle/v8.gyp
@@ -31,53 +31,20 @@
     {
       'target_name': 'v8',
       'type': 'none',
-      'conditions': [
-        ['want_separate_host_toolset==1', {
-          'toolsets': ['host', 'target'],
-        }, {
-          'toolsets': ['target'],
-        }],
-      ],
+      'toolsets': ['host', 'target'],
       'variables': {
-        'shim_headers_path': '<(SHARED_INTERMEDIATE_DIR)/shim_headers/<(_target_name)/<(_toolset)',
-      },
-      'include_dirs++': [
-        '<(shim_headers_path)',
-      ],
-      'all_dependent_settings': {
-        'include_dirs+++': [
-          '<(shim_headers_path)',
+        'headers_root_path': '../../include',
+        'header_filenames': [
+          'v8-debug.h',
+          'v8-preparser.h',
+          'v8-profiler.h',
+          'v8-testing.h',
+          'v8.h',
+          'v8stdint.h',
         ],
       },
-      'actions': [
-        {
-          'variables': {
-            'generator_path': '../../../tools/generate_shim_headers/generate_shim_headers.py',
-            'generator_args': [
-              '--headers-root', '../../include',
-              '--output-directory', '<(shim_headers_path)',
-              'v8-debug.h',
-              'v8-preparser.h',
-              'v8-profiler.h',
-              'v8-testing.h',
-              'v8.h',
-              'v8stdint.h',
-            ],
-          },
-          'action_name': 'generate_<(_target_name)_shim_headers',
-          'inputs': [
-            '<(generator_path)',
-          ],
-          'outputs': [
-            '<!@pymod_do_main(generate_shim_headers <@(generator_args) --outputs)',
-          ],
-          'action': ['python',
-                     '<(generator_path)',
-                     '<@(generator_args)',
-                     '--generate',
-          ],
-          'message': 'Generating <(_target_name) shim headers.',
-        },
+      'includes': [
+        '../../../build/shim_headers.gypi',
       ],
       'link_settings': {
         'libraries': [
@@ -88,13 +55,7 @@
     {
       'target_name': 'v8_shell',
       'type': 'none',
-      'conditions': [
-        ['want_separate_host_toolset==1', {
-          'toolsets': ['host'],
-        }, {
-          'toolsets': ['target'],
-        }],
-      ],
+      'toolsets': ['host', 'target'],
       'dependencies': [
         'v8'
       ],