[lldb][NFC] Fix build with GCC<6
GCC/libstdc++ before 6.1 can't handle scoped enums as unordered_map keys. LLVM
(and some build) bots officially support some GCC 5.x versions, so this patch
just makes the enum unscoped until we can require GCC 6.x.
teemperor on Jan 21 2021, 6:04 AM.Authored by