Reconsider UDP conduit default for run-tests on Cray XC

[Paul Hargrove]

I recently made the mistake of running CROSS=cray-aries-alps TERM=dumb PAGER=cat ./run-tests on Theta.
After churning for a long time saw an error message ending with:

In file included from /gpfs/mira-home/hargrove/upcxx-2019.9.0-rc1/.nobs/art/2367c8d4fd206ec1792b8a7af04c0f50493ba6cc/GASNet-stable/other/amudp/amudp_internal.h(9),
                 from /gpfs/mira-home/hargrove/upcxx-2019.9.0-rc1/.nobs/art/2367c8d4fd206ec1792b8a7af04c0f50493ba6cc/GASNet-stable/other/amudp/amudp_cdefs.c(6):
/gpfs/mira-home/hargrove/upcxx-2019.9.0-rc1/.nobs/art/2367c8d4fd206ec1792b8a7af04c0f50493ba6cc/GASNet-stable/other/amudp/../amx/amx_internal_fwd.h(12): catastrophic error: cannot open source file "amx_portable_platform.h"
  #include <amx_portable_platform.h>
                                    ^

compilation aborted for /gpfs/mira-home/hargrove/upcxx-2019.9.0-rc1/.nobs/art/2367c8d4fd206ec1792b8a7af04c0f50493ba6cc/GASNet-stable/other/amudp/amudp_cdefs.c (code 4)
Makefile:985: recipe for target 'amudp_cdefs.o' failed

IF one scrolls back far enough, the root cause becomes evident:

ERROR: udp-conduit support was not detected at configure time

So, this issue is intended to make a pair of observations:

1. that an auditor could easily make the same mistake I did
2. since CROSS names a network, this situation is avoidable with very little work

[Dan Bonachea]

The run-tests script has been retired

The new infrastructure correctly defaults to aries conduit on the Cray XC