[libcxxabi] [llvm] [ItaniumDemangle] Remove Named flag from OperatorInfo::Member entries (PR #136862)

[Michael Buch via llvm-commits]

Michael137 wrote:

@urnathan I couldn't really find an explanation for what "Not a nameable MemberExpr" are. Any idea if this is still needed? Test-suite runs cleanly without this

https://github.com/llvm/llvm-project/pull/136862