Revert r143972, which didn't actually compile under -Wnon-virtual-dtor.

(TIL: -Wnon-virtual-dtor is not in -Wall.)

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@144058 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed