Found that Crashing tests at some point in Clang
history were actually caught but testing on
Clang 6.0 and Clang 7.0 this is not the case.
So added Clang to the list of compilers that
don't run this tests. Noted that several
other Pull Requests were failing for the same
reason.
After some consideration I decided to just remove this test in debug
configurations. Many debuggers will behave as XCode does and try to
'catch' this by default. The test still works in release configs.
Fixes#45.
