Enhance GN diagnostic tools

tools/gn/gn.gyp

 {
   'variables': {
     'chromium_code': 1,
   },
   'targets': [
     {
       'target_name': 'gn_lib',
       'type': 'static_library',
       'dependencies': [
         '../../base/base.gyp:base',
@@ skipping 13 matching lines @@
         'builder.h',
         'builder_record.cc',
         'builder_record.h',
         'c_include_iterator.cc',
         'c_include_iterator.h',
         'command_args.cc',
         'command_check.cc',
         'command_desc.cc',
         'command_gen.cc',
         'command_help.cc',
+        'command_ls.cc',
         'command_refs.cc',
         'commands.cc',
         'commands.h',
         'config.cc',
         'config.h',
         'config_values.cc',
         'config_values.h',
         'config_values_extractors.cc',
         'config_values_extractors.h',
         'config_values_generator.cc',
@@ skipping 31 matching lines @@
         'input_conversion.cc',
         'input_conversion.h',
         'input_file.cc',
         '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',
         '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',
@@ skipping 103 matching lines @@
         'function_get_label_info_unittest.cc',
         'function_get_path_info_unittest.cc',
         'function_get_target_outputs_unittest.cc',
         'function_process_file_template_unittest.cc',
         'function_rebase_path_unittest.cc',
         'function_write_file_unittest.cc',
         'functions_target_unittest.cc',
         'functions_unittest.cc',
         'header_checker_unittest.cc',
         'input_conversion_unittest.cc',
+        'label_pattern_unittest.cc',
         'label_unittest.cc',
         'loader_unittest.cc',
         'ninja_action_target_writer_unittest.cc',
         'ninja_binary_target_writer_unittest.cc',
         'ninja_copy_target_writer_unittest.cc',
         'ninja_target_writer_unittest.cc',
         'ninja_toolchain_writer_unittest.cc',
         'operators_unittest.cc',
         'parse_tree_unittest.cc',
         'parser_unittest.cc',
@@ skipping 26 matching lines @@
       'type': 'executable',
       'sources': [
         'generate_test_gn_data.cc',
       ],
       'dependencies': [
         '../../base/base.gyp:base',
       ],
     }
   ],
 }