p Runs the 'empty_main' test within the simulator

$ $SG_TEST_EXENV ./empty_main_simulator${EXEEXT:=} ${srcdir:=.}/../../../examples/msg/small_platform.xml ${srcdir:=.}/empty_main.xml
> [Tremblay:server:(1) 0.000000] [gras/INFO] Exiting GRAS
> [Fafard:client:(2) 0.000000] [gras/INFO] Exiting GRAS