Un-nest configs in GN files.

third_party/lzma_sdk/BUILD.gn

 # Copyright 2014 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.
 
 config("lzma_sdk_config") {
   include_dirs = [ "." ]
 }
 
+# Must be in a config because of how GN orders flags (otherwise -Wall will
+# appear after this, and turn it back on).
+config("clang_warnings") {
+  if (is_clang) {
+    # Upstream uses self-assignment to avoid warnings.
+    cflags = [ "-Wno-self-assign" ]
+  }
+}
+
 static_library("lzma_sdk") {
   sources = [
     "7z.h",
     "7zAlloc.c",
     "7zAlloc.h",
     "7zBuf.c",
     "7zBuf.h",
     "7zCrc.c",
     "7zCrc.h",
     "7zCrcOpt.c",
@@ skipping 24 matching lines @@
     "LzmaLib.h",
     "Types.h",
   ]
 
   defines = [
     "_7ZIP_ST",
     "_LZMA_PROB32",
   ]
 
   configs -= [ "//build/config/compiler:chromium_code" ]
-  configs += [ "//build/config/compiler:no_chromium_code" ]
-
+  configs += [
+    ":clang_warnings",
+    "//build/config/compiler:no_chromium_code",
+  ]
   public_configs = [ ":lzma_sdk_config" ]
-
-  # Must be in a config because of how GN orders flags (otherwise -Wall will
-  # appear after this, and turn it back on).
-  config("clang_warnings") {
-    if (is_clang) {
-      # Upstream uses self-assignment to avoid warnings.
-      cflags = [ "-Wno-self-assign" ]
-    }
-  }
-  configs += [ ":clang_warnings" ]
 }