The OPAL_ENABLE_MULTI_THREADS macro is always defined as 1. This was
causing us to always use the multi-thread path for synchronization
objects. The code has been updated to use the opal_using_threads()
function. When MPI_THREAD_MULTIPLE support is disabled at build time
(2.x only) this function is a macro evaluating to false so the
compiler will optimize out the MT-path in this case. The
OPAL_ATOMIC_ADD_32 macro has been removed and replaced by the existing
OPAL_THREAD_ADD32 macro.
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>
143a93f379