swift234

[CodeCompletion] Fix dot completion with non-nominals

Completion after dot inside an init (or any other parent expr with a
nominal type) was incorrectly looking at the types of parent expressions
whenever the base type was not a nominal (even an lvalue of a nominal
wasn't working).  This code to look at the type of the parent was never
correct, and fortunately the type-checking issues that prompted it to be
added in the first place have since been fixed, so we can just delete
it.

rdar://problem/25773358