Add Kokoro build configuration files

Bug: tint:652
Change-Id: Ifd9d6f9dde9c01c4c64e9c2bc59395ef049dd54b
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/44872
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Reviewed-by: David Neto <dneto@google.com>

kokoro/linux/cmake-clang-debug/build.sh

@@ -0,0 +1,25 @@
+#!/bin/bash
+
+# Copyright 2021 The Tint Authors.
+#
+# 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.
+
+set -e # Fail on any error.
+
+SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd )"
+
+export BUILD_SYSTEM=cmake
+export BUILD_TOOLCHAIN=clang
+export BUILD_TYPE=Debug
+
+${SCRIPT_DIR}/../build.sh

kokoro/linux/cmake-clang-debug/presubmit.cfg

@@ -0,0 +1,3 @@
+# Format: //devtools/kokoro/config/proto/build.proto
+
+build_file: "tint/kokoro/linux/cmake-clang-debug/build.sh"