(like in vcl/inc/osx/a11ywrapper.h's AquaA11yWrapper), at least on recent Clang
trunk, from within the call to cast() in

  cast<RecordDecl>(getDeclContext())

as the decl context apparently is something other than a RecordDecl.

Change-Id: I238bae44d6db0f04bf8f90b0032489e3b4822eee