[PATCH] libstdc++: Improve code generation for atomic reference counting

2 of expected failures 65 of unsupported tests 244 --- 2016-11-09 Pauli Nieminen * include/ext/atomicity.h (__exchange_and_add): Optimize negative add with builtin __atomic_fetch_sub. (__atomic_add): Call __exchange_and_add to reuse same code

[PATCH] libstdc++: Allow using without lock free atomic int

--- 2016-11-09 Pauli Nieminen * include/std/future: Remove check for ATOMIC_INT_LOCK_FREE * libsupc++/eh_ptr.cc (exception_ptr::_M_addref) (exception_ptr::_M_release) (__gxx_dependent_exception_cleanup) (rethrow_exception): Use atomicity.h reference c