Add Kokoro bots for building using Bazel.

kokoro/macos-clang-release-bazel/build.sh

@@ -0,0 +1,38 @@
+#!/bin/bash
+# Copyright (c) 2019 Google LLC.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# macOS Build Script.
+
+# Fail on any error.
+set -e
+# Display commands being run.
+set -x
+
+CC=clang
+CXX=clang++
+SRC=$PWD/github/glslang
+cd $SRC
+
+# Get bazel 0.29.1.
+gsutil cp gs://bazel/0.29.1/release/bazel-0.29.1-darwin-x86_64 .
+chmod +x bazel-0.29.1-darwin-x86_64
+
+echo $(date): Build everything...
+./bazel-0.29.1-darwin-x86_64 build :all
+echo $(date): Build completed.
+
+echo $(date): Starting bazel test...
+./bazel-0.29.1-darwin-x86_64 test :all
+echo $(date): Bazel test completed.