Make type assumptions when using Boolean function

[strblr]

Suggestion

Right now, only the last instruction fails in TS with the error Object is possibly 'null' :

declare const value: null | { x: number };

const foo = value && value.x;
const bar = !!value && value.x;
const baz = Boolean(value) && value.x;

Playground

Since it's strictly equivalent to the instruction just above, I suggest making the same type assumptions.

🔍 Search Terms

Boolean, function, inference, assumption, assertion

✅ Viability Checklist

My suggestion meets these guidelines:

• This wouldn't be a breaking change in existing TypeScript/JavaScript code
• This wouldn't change the runtime behavior of existing JavaScript code
• This could be implemented without emitting different JS based on the types of the expressions
• This isn't a runtime feature (e.g. library functionality, non-ECMAScript syntax with JavaScript output, new syntax sugar for JS, etc.)
• This feature would agree with the rest of TypeScript's Design Goals.

[MartinJohns]

Duplicate of #16655.