new solver has problems with generic typing

[idk-i-reportbugs]

---

this code raises 2 errors:

local function lerp<T>(a: T, b: T, t: number): T
	if type(a) ~= type(b) or (type(a) ~= "number" and type(a) ~= "vector") then
		warn(`Unable to cast {typeof(a)} to number or vector`)
		return a
	end
	return a + (b - a) * t
end

Error 1:
line 2 gives the error: Type function instance union<*blocked-203614*, nil> is uninhabited
entire line was highlighted, except if and then

Error 2:
normally, line 6 should detect that generic type T should either be number, Vector3 or Vector2 (because of the ifs at line 2-5)
however, that doesn't happen. Instead, I get an error at line 6: Type function instance intersect<T, number> is uninhabited

---

Moreover, it seems like typechecking has problems with for i, v in table do, where pairs, ipairs or next is omitted
Error message: Cannot iterate over a table without indexer
the table:

type RigAnimationAxisTable<T> = {
	RootJoint: T,
	Neck: T,
	["Right Shoulder"]: T,
	["Left Shoulder"]: T,
	["Right Hip"]: T,
	["Left Hip"]: T,
}

local joint_names: RigAnimationAxisTable<true> = {
	RootJoint = true,
	Neck = true,
	["Right Shoulder"] = true,
	["Left Shoulder"] = true,
	["Right Hip"] = true,
	["Left Hip"] = true,
}

• all of these use strict typechecking
• after a bit of checking, issue 1 seems to apply anytime i use a generic type in a similar way, and then try to check the type of said parameter

[AshleyFlow]

I've found a similar issue with generics... intersections?...

local function foo<T>(bar: number & T)
	assert(typeof(bar) == "number")

	typeof(bar) -- TypeError: Type function instance intersect<T & number, number> is uninhabited
end

after the assertion bar turns into intersect<T & number, number> which causes the type error