Minor buddy alloc tweaks; Share entire allocator testing infrastructure

tests/allocators/forever.js

@@ -0,0 +1,16 @@
+var child_process = require("child_process");
+
+// restarts the test forever, that is, until an issue is detected
+
+var count = 0;
+while (true) {
+  console.log("[ #" + ++count + " ]\n");
+  var script = process.argv.length > 2
+    ? __dirname + "/" + process.argv[2]
+    : __dirname;
+  var res = child_process.spawnSync("node", [ script ], { stdio: "inherit" });
+  if (res.status !== 0)
+    throw Error("exited with " + res.status);
+  if (res.error)
+    throw res.error;
+}