New Solver: Assert corrupts/erase Instance variable type

[ArchLand64]

I get a false type error and the type of weld incorrectly becomes never after an assert with the new Luau type solver enabled in Roblox Studio. weld should remain a WeldConstraint and part1 should be a BasePart after my asserts.

local weld = Instance.new("WeldConstraint")
assert(weld.Part1)
print(weld) --hover type incorrectly becomes `never`
assert(weld.Part1.Name == "RootPart")
local part1 = assert(weld.Part1)
print(part1.Position) --TypeError: Type '~(false?)' does not have key 'Position' Luau(1002)

[aatxe]

This is caused by refinements producing intersections between the class types and table types with the specified properties, and then normalization is turning any intersection of a class with a table into never.

[alexmccord]

Same as https://github.com/luau-lang/luau/issues/1261.