When UPC sampling is available, call BGP_UPC_Initialize() in every process, not just those on core 0.  Otherwise, BGP_UPC_Initialize will block forever waiting on the other processes to also call it.
When UPC sampling is available, call BGP_UPC_Initialize()
in every process, not just those on core 0.  Otherwise,
BGP_UPC_Initialize will block forever waiting on the other
processes to also call it.

zcth428/hpctoolkit,HPCToolkit/hpctoolkit,HPCToolkit/hpctoolkit,zcth428/hpctoolkit,zcth428/hpctoolkit,HPCToolkit/hpctoolkit,HPCToolkit/hpctoolkit,zcth428/hpctoolkit111,HPCToolkit/hpctoolkit,HPCToolkit/hpctoolkit,zcth428/hpctoolkit111,zcth428/hpctoolkit111,zcth428/hpctoolkit,zcth428/hpctoolkit,zcth428/hpctoolkit111,zcth428/hpctoolkit111