Bugs in URL implementation

[piscisaureus]

// Setting `.port` should update only the receiver.
const u1 = new URL("http:https://google.com/");
const u2 = new URL(u1);
u2.port = 123;
assertStrictEquals(u1.port, "");

// URLSearchParams identity should not be lost when URL is updated.
const u = new URL("http:https://foo.com/");
const sp1 = u.searchParams;
u.href = "http:https://bar.com/?baz=42";
const sp2 = u.searchParams;
assertStrictEquals(sp1, sp2);

[nayeemrmn]

Fixed by #9276.