Fix blocked-type leak when assigning global with the same global name

[karl-police]

Fixes #1946

--!strict
a = a
function a:test() end

I was trying to find what would be the correct fix, that much, that it made me mad, because there's no way for me to figure it out, unless I learn everything that is contained inside this repository, or something and understand it.

 

This adds FFlagLuauFixPrepopulateGlobalOnSameGlobal

If there's a
a = a the rhs gets banned from the prepopulator :). 🤷

Maybe my idea is stupid or maybe not. Lemme know, thanks.

 

The reason on why the prepopulator is because I set breakpoints and it's something that starts happening in the ConstraintGenerator.

I made comparisons with a bugged vs. non-bugged one, for instance

 

Why are rhs values even going into a collection that is named globalScope->lvalueTypes though?

Were rhs values ever intended to be processed by the visitor?

[karl-police]

I probably have to re-order the if statement, I noticed it can be made a bit better. But I will leave it like this for now until I get opinions about this fix. 🤔