Drop windows specific handling of equivalent destructors.

Now that the relevant tests use -mconstructor-aliases and the missing
features have been implemented, we can just drop this.

No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@194595 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed