Implement a GCC compatible SEH unwinding personality, __gxx_personality_seh0

This allows handling SEH based exceptions, with unwind functions
provided by libgcc.

Differential Revision: https://reviews.llvm.org/D49638

git-svn-id: https://llvm.org/svn/llvm-project/libcxxabi/trunk@337754 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed