'bigint' is not comparable to 'number' with loose equality

TypeScript Version: 3.3.3

Search Terms: bigin == number not comparable loose equality

Code

1n == 1

error:

This condition will always return 'false' since the types 'bigint' and 'number' have no overlap.

but in chrome 72.0.3626.121

> 1n == 1
< true

and in MDN https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/BigInt

And similar issues

let x = [1, 2, 3]
x[1n]

error:

Type '1n' cannot be used as an index type.

in Chrome

>  let x = [1, 2, 3]
   x[1n]
<  2

Playground Link:
http://www.typescriptlang.org/play/index.html#src=1n%20%3D%3D%201
http://www.typescriptlang.org/play/index.html#src=let%20x%20%3D%20%5B1%2C%202%2C%203%5D%0D%0Ax%5B1n%5D

Related Issues:
https://github.com/Microsoft/TypeScript/issues/30655

Start with the two TypeScript 3.3.3 reproductions in the issue: loose equality between 1n and 1, and indexing an array with 1n. Compare the reported TypeScript errors with the Chrome and MDN behavior, then review related issue #30655. Done means the intended BigInt behavior is resolved consistently for both examples and verified with regression coverage.