url: fix port overflow checking

This patch adds (port > 0xffff) check after each digit in the loop and prevents integer overflow.

In the current implementation a result can be incorrect if an integer overflow occurs. For example:

const URL = require('url').URL;
const url = new URL("http://example.com:4294967377/");
console.log(url.port);
// actual: 81
// expected: failure (TypeError)

Refs: https://github.com/w3c/web-platform-tests/pull/7602

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• commit message follows commit guidelines

Affected core subsystem(s)

url