[lldb][NFC] Remove unused CompilerType memory functions

Summary:
All these functions are unused from what I can see. Unless I'm missing something here, this code
can go the way of the Dodo.

Reviewers: labath

Reviewed By: labath

Subscribers: abidh, JDevlieghere, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D70770