for constructors and destructors since the original declaration given
by the AT_specification both won't and can't.
Patch by Yacine Belkadi, I've cleaned up the testcases.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181471 91177308-0d34-0410-b5e6-96231b3b80d8