Error on multiple files with same basenames in target.

test/same-name/src/all.gyp

 # Copyright (c) 2009 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': 'prog1',
       'type': 'executable',
       'defines': [
         'PROG="prog1"',
       ],
       'sources': [
         'prog1.c',
         'func.c',
-        # Uncomment to test same-named files in different directories,
-        # which Visual Studio doesn't support.
-        #'subdir1/func.c',
-        #'subdir2/func.c',
       ],
     },
     {
       'target_name': 'prog2',
       'type': 'executable',
       'defines': [
         'PROG="prog2"',
       ],
       'sources': [
         'prog2.c',
         'func.c',
-        # Uncomment to test same-named files in different directories,
-        # which Visual Studio doesn't support.
-        #'subdir1/func.c',
-        #'subdir2/func.c',
       ],
     },
   ],
 }