Pull boringssl generated source from boringssl_gen

third_party/boringssl/boringssl_configurations.gypi

-# Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
-# for details. All rights reserved. Use of this source code is governed by a
-# BSD-style license that can be found in the LICENSE file.
-
-# This file is included to modify the configurations to build third-party
-# code from BoringSSL.
-{
-  'target_defaults': {
-    'conditions': [
-      ['OS == "linux" or OS == "android"', {
-        'cflags_c': [
-          '-std=c99',
-        ],
-        'defines': [
-          '_XOPEN_SOURCE=700',
-        ],
-      }],
-    ],
-    # Removes these flags from the list cflags.
-    'cflags!': [
-      '-ansi',
-      # Not supported for C, only for C++.
-      '-Wnon-virtual-dtor',
-      '-Wno-conversion-null',
-      '-fno-rtti',
-      '-fvisibility-inlines-hidden',
-      '-Woverloaded-virtual',
-    ],
-  },
-}