Maybe this patch isn't the only way to skin this cat. I guess that `typedTreeAt` finds the inner apply in `ApplyImplicitArgs(Apply("map")("x => x")("canBuildFrom")`, and we compensate here by typechecking that against a wildcard expected type, which wraps another `ApplyImplicitArgs` node around this.

An alternative fix would be to change `typedTreeAt` to pick a directly enclosing `ApplyImplicitArgs` node, if one exists.