Add Ninja support for MSVS $(TargetExt), $(TargetFileName) and $(TargetPath) macros.

test/win/vs-macros/targetext.gyp

-# Copyright (c) 2012 Google Inc. All rights reserved.
+# Copyright (c) 2014 Google Inc. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 {
  'targets': [
     {
-      'target_name': 'test_output_exe',
+      'target_name': 'test_targetext_executable',
       'type': 'executable',
+      'sources': ['hello.cc'],
       'msvs_settings': {
         'VCLinkerTool': {
-          'OutputFile': '$(OutDir)\\blorp.exe'
+          'OutputFile': '$(TargetDir)\\executable$(TargetExt)',
         },
       },
-      'sources': ['hello.cc'],
     },
     {
-      'target_name': 'test_output_exe2',
-      'type': 'executable',
+      'target_name': 'test_targetext_loadable_module',
+      'type': 'loadable_module',
+      'sources': ['hello.cc'],
       'msvs_settings': {
         'VCLinkerTool': {
-          'OutputFile': '$(OutDir)\\subdir\\blorp.exe'
+          'OutputFile': '$(TargetDir)\\loadable_module$(TargetExt)',
         },
       },
-      'sources': ['hello.cc'],
     },
     {
-      'target_name': 'test_output_dll',
+      'target_name': 'test_targetext_shared_library',
       'type': 'shared_library',
+      'sources': ['hello.cc'],
       'msvs_settings': {
         'VCLinkerTool': {
-          'OutputFile': '$(OutDir)\\blorp.dll'
+          'OutputFile': '$(TargetDir)\\shared_library$(TargetExt)',
         },
       },
-      'sources': ['hello.cc'],
     },
     {
-      'target_name': 'test_output_lib',
+      'target_name': 'test_targetext_static_library',
       'type': 'static_library',
+      'sources': ['hello.cc'],
       'msvs_settings': {
         'VCLibrarianTool': {
-          'OutputFile': '$(OutDir)\\blorp.lib'
+          'OutputFile': '$(TargetDir)\\static_library$(TargetExt)',
         },
       },
-      'sources': ['hello.cc'],
     },
     {
-      'target_name': 'test_output_lib2',
-      'type': 'static_library',
+      'target_name': 'test_targetext_product_extension',
+      'type': 'executable',
+      'sources': ['hello.cc'],
+      'product_extension': 'library',
       'msvs_settings': {
-        'VCLibrarianTool': {
-          'OutputFile': '$(OutDir)\\subdir\\blorp.lib'
+        'VCLinkerTool': {
+          'OutputFile': '$(TargetDir)\\product_extension$(TargetExt)',
         },
       },
-      'sources': ['hello.cc'],
     },
   ]
 }