[Demangle] remove itaniumFindTypesInMangledName
[Demangle] remove itaniumFindTypesInMangledName

Summary:
This (very specialized) function was added to enable an LLDB use case.
Now that a more generic interface (overriding of parser functions -
D52992)  is available, and LLDB has been converted to use that (D54074),
the function is unused and can be removed.

Reviewers: erik.pilkington, sgraenitz, rsmith

Subscribers: mgorny, hiraditya, christof, libcxx-commits, llvm-commits

Differential Revision: https://reviews.llvm.org/D54893

git-svn-id: 6a9f6578bdee8d959f0ed58970538b4ab6004734@347670 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/libcxxabi,llvm-mirror/libcxxabi,llvm-mirror/libcxxabi,llvm-mirror/libcxxabi,llvm-mirror/libcxxabi