When Clang encounters an already invalid class declaration, it can emit incorrect diagnostics about the exception specification on some of its members. This patch temporarily works around that incorrect diagnostic. The clang bug was introduced in r324062. git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@324164 91177308-0d34-0410-b5e6-96231b3b80d8