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

build/config/BUILDCONFIG.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.
 
 # =============================================================================
 # PLATFORM SELECTION
 # =============================================================================
 #
 # There are two main things to set: "os" and "cpu". The "toolchain" is the name
 # of the GN thing that encodes combinations of these things.
@@ skipping 431 matching lines @@
 # Set up the default configuration for every build target of the given type.
 # The values configured here will be automatically set on the scope of the
 # corresponding target. Target definitions can add or remove to the settings
 # here as needed.
 
 # Holds all configs used for making native executables and libraries, to avoid
 # duplication in each target below.
 _native_compiler_configs = [
   "//build/config:feature_flags",
   "//build/config/compiler:compiler",
+  "//build/config/compiler:clang_stackrealign",
   "//build/config/compiler:compiler_arm_fpu",
   "//build/config/compiler:chromium_code",
   "//build/config/compiler:default_include_dirs",
   "//build/config/compiler:default_optimization",
   "//build/config/compiler:default_symbols",
   "//build/config/compiler:no_rtti",
   "//build/config/compiler:runtime_library",
   "//build/config/sanitizers:default_sanitizer_flags",
   "//build/config/sanitizers:default_sanitizer_coverage_flags",
 ]
@@ skipping 139 matching lines @@
     forward_variables_from(invoker, "*")
 
     # All shared libraries must have the sanitizer deps to properly link in
     # asan mode (this target will be empty in other cases).
     if (!defined(deps)) {
       deps = []
     }
     deps += [ "//build/config/sanitizers:deps" ]
   }
 }