Fix type of `__cxa_allocate_exception` with recent libsupc++.
Recent versions of GNU libsupc++ provide a definition of `__cxa_allocate_exception` that has a `noexcept` qualifier. This is sensible (if allocating an exception throws an exception, then something is badly wrong) but it not what the ABI spec says. We provide our own definition of this, which must match another if provided.
This wouldn't normally be a problem, but recent libstdc++ headers appear to leak libsupc++ headers into the namespace, so we're seeing these definitions even without explicitly including any C++ ABI-related headers.
clang trunk if -fobjc-runtime-1.7 is specified and provides significantly
better interoperability with foreign exceptions.
Note: Most of the exception tests will not pass with gcc or clang < 3.3. They
test things that are impossible to implement quite correctly with the
GCC-compatible exception ABI.
Also updated the release notes to reflect recent improvements.
Jason Barmparesos
theraven