Mark Thread As Running

#   ROUTINE: Mark Thread As Running
#       Marks specified thread as in use.
#       Parameters:
#           r4 = (threadIndex) Specified thread index

8014c924: 3c028016 lui r2,0x8016
8014c928: 8c425f98 lw r2,0x5f98(r2)                     #   threads
8014c92c: 00042280 sll r4,r4,0x0a                       #   threadIndex * sizeof(thread)
8014c930: 00822021 addu r4,r4,r2                        #   threads[threadIndex]
8014c934: 34020001 ori r2,r0,0x0001
8014c938: 03e00008 jr r31
8014c93c: ac820048 sw r2,0x0048(r4)                     #   threads[threadIndex].isRunning = true