Unintentional bugfix?: Type parameters no longer assignable to unions with `object` and `undefined` in strict null checks

[weswigham]

TypeScript Version: 2.9.0-dev.20180509

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Code

function f<T>(x: T) {
    const y: object | null | undefined = x;
}

in 2.8 with strictNullChecks on, this compiles (it does not when it is off). In very recent master, however, it is now an error (as it should be?):

Playground Link

While I think the error is certainly correct to issue, this change apparently breaks a handful of RWC tests, so is worth looking into.

[weswigham]

Intentional fix by #23806, I just wasn't aware of it. 👍