typings: add typing for TypedArrayPrototypeFill

[jazelly]

No description provided.

[aduh95]

Why this one in particular? Looking at https://tc39.es/ecma262/#sec-properties-of-the-%typedarrayprototype%-object there are many that are missing – and I guess that's fine as long as we're not using them

[jazelly]

No specific reason : ) just saw this while looking at the lib/buffer.js code.

node/lib/buffer.js

Line 614 in 264cad7

TypedArrayPrototypeFill(buffer, 0, pos, length);

Didn't check if other functions that might be missing. Maybe it's a good time to do so tho.

[jazelly]

Actually you are right, there are many TypedArray methods we used without typing. I'll re-raise this for the domain together.