trim
Answer a type that includes at least all values from the receiver that aren't also in the typeToRemove. Note that the answer can be conservatively large, and is typically just the receiver, even if the types overlap.
The resulting type must include every element of the receiver that isn't in typeToRemove, but it may include additional elements that are in both the receiver and typeToRemove. It must not include elements that were not in the receiver.
The receiver may be destroyed or recycled if it's mutable.
This provides an opportunity to tighten the bounds for integer ranges, or reduce the element and size bounds on map/tuple/set types.