Renaming to coincide with updated tagging system.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/branches/release_350@215006 91177308-0d34-0410-b5e6-96231b3b80d8
Revert renaming. Should rename tags instead.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/branches/release_35@215016 91177308-0d34-0410-b5e6-96231b3b80d8