Special-case paths that appear in libs by not prefixing them with -l.

tools/gn/gn.gyp

 {
   'variables': {
     'chromium_code': 1,
   },
   'targets': [
     {
       'target_name': 'gn_lib',
       'type': 'static_library',
       'dependencies': [
         '../../base/base.gyp:base',
@@ skipping 78 matching lines @@
         'input_file.h',
         'input_file_manager.cc',
         'input_file_manager.h',
         'item.cc',
         'item.h',
         'label.cc',
         'label.h',
         'label_pattern.cc',
         'label_pattern.h',
         'label_ptr.h',
+        'lib_file.cc',
+        'lib_file.h',
         'loader.cc',
         'loader.h',
         'location.cc',
         'location.h',
         'ninja_action_target_writer.cc',
         'ninja_action_target_writer.h',
         'ninja_binary_target_writer.cc',
         'ninja_binary_target_writer.h',
         'ninja_build_writer.cc',
         'ninja_build_writer.h',
@@ skipping 176 matching lines @@
           'dependencies': [
             'gn_unittests',
           ],
           'includes': [ '../../build/isolate.gypi' ],
           'sources': [ 'gn_unittests.isolate' ],
         },
       ],
     }],
   ],
 }