Add asm.js sanity test.

tools/check_web_sanity.js

@@ -0,0 +1,31 @@
+#! /usr/bin/env nodejs
+// Copyright 2022 Bradley D. Nelson
+//
+// 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.
+
+var fs = require('fs');
+var process = require('process');
+
+var source = fs.readFileSync(process.stdin.fd).toString();
+
+if (source.match(/Invalid/)) {
+  console.log('BAD ASM.JS');
+  console.log(source);
+  process.exit(1)
+}
+
+if (!source.match(/[-][-][>] 123[ \r\n]+$/)) {
+  console.log('MISSING EXPECTED OUTPUT');
+  console.log(source);
+  process.exit(1)
+}