Update from https://crrev.com/320343

tools/clang/scripts/update.sh

 #!/usr/bin/env bash
 # Copyright (c) 2012 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.
 
 # This script will check out llvm and clang into third_party/llvm and build it.
 
 # Do NOT CHANGE this if you don't know what you're doing -- see
 # https://code.google.com/p/chromium/wiki/UpdatingClang
 # Reverting problematic clang rolls is safe, though.
-CLANG_REVISION=231191
+CLANG_REVISION=231690
 
 # This is incremented when pushing a new build of Clang at the same revision.
 CLANG_SUB_REVISION=1
 
 PACKAGE_VERSION="${CLANG_REVISION}-${CLANG_SUB_REVISION}"
 
 THIS_DIR="$(dirname "${0}")"
 LLVM_DIR="${THIS_DIR}/../../../third_party/llvm"
 LLVM_BUILD_DIR="${LLVM_DIR}/../llvm-build/Release+Asserts"
 COMPILER_RT_BUILD_DIR="${LLVM_DIR}/../llvm-build/compiler-rt"
@@ skipping 652 matching lines @@
 
 if [[ -n "$run_tests" ]]; then
   # Run Chrome tool tests.
   ninja -C "${LLVM_BUILD_DIR}" cr-check-all
   # Run the LLVM and Clang tests.
   ninja -C "${LLVM_BUILD_DIR}" check-all
 fi
 
 # After everything is done, log success for this revision.
 echo "${PACKAGE_VERSION}" > "${STAMP_FILE}"