[GC] Remove a bunch of unused complexity from Registry and RegistryParser [NFCI]
The only two Registries we have in the system are the GCStrategy and GCMetadataPrinter ones. Registry has a bunch of problems - for instance, order of initialization is undefined - and the code was overly general for what was actually used. I hope to completely kill Registry in the near future, but for now, just delete all the unused listener and parsing support.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257727
91177308-0d34-0410-b5e6-
96231b3b80d8
OSDN Git Service
