This actually saves 11 bytes of gzip size. Gzip is some dark magic.
This only adds 10 bytes to the gzip file size, so the added readability seems worth it.
Note that Node's own native implementation of setImmediate neglects to support this behavior, so I have shimmed global.setImmediate in test/tests.js in order to make the new test pass in Node. We might want to think about shimming global.setImmediate in setImmediate.js, too, but @domenic thinks we should wait until someone complains, and I agree.
A savings of 46 bytes uglified.
18 bytes isn't a huge savings, but this code works even when the global variable is not already defined, in any JS environment.
A savings of 24 bytes uglified.
A savings of 63 bytes uglified.
A savings of 35 bytes.
A savings of 36 bytes.
A savings of 71 bytes uglified.
A savings of 55 bytes uglified.
This change alone reduces the uglified size by 340 bytes.
Note that this removes support for string handlers, as none of the informal specifications of setImmediate speak of that behavior.