This originally came up as an issue with libc++abi support (#152), but is not specific to that ABI.
* Use the C++ runtime to check for uncaught C++ exceptions.
As discussed in #152, use the function defined in the Itanium C++ ABI to
check whether the thrown exception is the current caught C++ exception
and needs rethrowing via `__cxa_rethrow()`.
Co-authored-by: Niels Grewe <grewe@ocean-insights.com>
Co-authored-by: David Chisnall <gnustep@theravensnest.org>
Frederik Seiffert