Type guard/Equality narrowing doesn't work on "any"

Bug Report

🔎 Search Terms

type guard equality narrowing strict equal equality

🕗 Version & Regression Information

• This is the behavior in every version I tried, and I found earlier issues (https://github.com/microsoft/TypeScript/pull/9407 and the PR that added this feature https://github.com/microsoft/TypeScript/pull/9407)

⏯ Playground Link

https://www.typescriptlang.org/play?#code/FAMwrgdgxgLglgewgAgEYEMBOAKZWDmAXHhAJ7ICUyA3sMvcnCMrgcgLyfIRgA2vlGnQYjMAUxhhMKAgG5h9AL7AFjZq0z4OXEOl4BnMYNojREqTM3yRy5SqA

💻 Code

function bar( arg: any ) {
    if ( arg === null ) {
        return arg;
    }

    if ( arg === false ) {
        return arg;
    }
}

🙁 Actual behavior

arg should be null/false inside the if conditions

🙂 Expected behavior

arg is any

The docs say this should work https://www.typescriptlang.org/docs/handbook/2/narrowing.html
When using unknown instead of any it works perfectly fine. I think adjusting this, so it works for any too, isn't too far fetched.

Reproduce the narrowing behavior in the linked TypeScript Playground and compare it with the documented behavior for unknown. Trace the type-checker path for equality narrowing of any, then add regression coverage showing null and false are narrowed as expected and run the relevant compiler tests.