Add atomic_t<>::observe() (relaxed load)
Add atomic_fence_XXX() (barrier functions)
Get rid of MFENCE instruction, replace with no-op LOCK OR on stack.
Remove <atomic> dependence from stdafx.h and relevant headers.
Use -fno-exceptions in cmake.
On MSVC, enable _HAS_EXCEPTION=0.
Cleanup throw/catch from the source.
Create yaml.cpp enclave because it needs exception to work.
Disable thread_local optimizations in logs.cpp (TODO).
Implement cpu_counter for cpu_threads (moved globals).