Recommit r256322: Fix PR25898 - Check for incomplete pointers types in can_catch(...)

This patch re-commits r256322 and r256323. They were reverted due to a OS X
test failure. The test failure has been fixed by libc++ commit r258217.

This patch also adds some additional tests.


git-svn-id: https://llvm.org/svn/llvm-project/libcxxabi/trunk@258249 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed