GN: Move x86 Clang -mstackrealign workaround to its own config, elide it where problematic

components/crash/content/app/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.
 
 if (is_android) {
   import("//build/config/android/config.gni")
 }
 
 source_set("lib") {
   sources = [
@@ skipping 98 matching lines @@
     "//base:base_static",
     "//components/crash/core/common",
     "//content/public/common:content_descriptors",
     "//content/public/common:result_codes",
   ]
 
   if (is_android) {
     defines += [ "CHROME_BUILD_ID=\"$android_chrome_build_id\"" ]
   }
 
-  if (current_cpu == "x86" && is_clang) {
-    # Clang's -mstackrealign doesn't work well with
-    # linux_syscall_support.h hand written asm syscalls.
-    # See https://crbug.com/556393
-    cflags -= [ "-mstackrealign" ]
-  }
+  # Clang's -mstackrealign doesn't work well with
+  # linux_syscall_support.h hand written asm syscalls.
+  # See https://crbug.com/556393
+  configs -= [ "//build/config/compiler:clang_stackrealign" ]
 
   if (is_win) {
     deps += [
       "//breakpad:breakpad_handler",
       "//sandbox",
 
       #'../breakpad/breakpad.gyp:breakpad_sender',  TODO(GYP)
     ]
   } else if (is_posix && !is_ios) {
     deps += [ "//breakpad:client" ]
@@ skipping 34 matching lines @@
 
     if (is_mac) {
       deps += [ "//breakpad" ]
     }
 
     if (is_win) {
       deps += [ "//breakpad:breakpad_handler" ]
     }
   }
 }