Implement `gn analyze`.

tools/gn/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//testing/test.gni")
 import("//testing/libfuzzer/fuzzer_test.gni")
 
 defines = [ "GN_BUILD" ]
 
 static_library("gn_lib") {
   configs += [ "//build/config:precompiled_headers" ]
 
   sources = [
     "action_target_generator.cc",
     "action_target_generator.h",
     "action_values.cc",
     "action_values.h",
+    "analyzer.cc",
+    "analyzer.h",
     "args.cc",
     "args.h",
     "binary_target_generator.cc",
     "binary_target_generator.h",
     "build_settings.cc",
     "build_settings.h",
     "builder.cc",
     "builder.h",
     "builder_record.cc",
     "builder_record.h",
     "bundle_data.cc",
     "bundle_data.h",
     "bundle_data_target_generator.cc",
     "bundle_data_target_generator.h",
     "bundle_file_rule.cc",
     "bundle_file_rule.h",
     "c_include_iterator.cc",
     "c_include_iterator.h",
+    "command_analyze.cc",
     "command_args.cc",
     "command_check.cc",
     "command_clean.cc",
     "command_desc.cc",
     "command_format.cc",
     "command_gen.cc",
     "command_help.cc",
     "command_ls.cc",
     "command_path.cc",
     "command_refs.cc",
@@ skipping 221 matching lines @@
     ":last_commit_position",
     "//base",
     "//build/config/sanitizers:deps",
     "//build/win:default_exe_manifest",
   ]
 }
 
 test("gn_unittests") {
   sources = [
     "action_target_generator_unittest.cc",
+    "analyzer_unittest.cc",
     "args_unittest.cc",
     "builder_unittest.cc",
     "c_include_iterator_unittest.cc",
     "command_format_unittest.cc",
     "config_unittest.cc",
     "config_values_extractors_unittest.cc",
     "escape_unittest.cc",
     "exec_process_unittest.cc",
     "filesystem_utils_unittest.cc",
     "function_foreach_unittest.cc",
@@ skipping 62 matching lines @@
 }
 
 fuzzer_test("gn_parser_fuzzer") {
   sources = [
     "parser_fuzzer.cc",
   ]
   deps = [
     ":gn_lib",
   ]
 }