basic mapping function fails in new solver

[jackdotink]

local function map<T, U>(v: T, fn: (T) -> U): U
	return fn(v)
end

local a = map(5, function(x)
	return x * 2
end)

The above code gives the type error Consider placing the following annotations on the arguments: x: number or instead annotating the return as number on the function expression passed in the call to map.

Luau should infer x to be number without an annotation.