added test program for registers
added test program for registers

p4lang/p4c-bm,hanw/p4c-bm,ops-p4/ops-p4c,ops-p4/ops-p4c,ops-p4/ops-p4c,p4lang/p4c-bm,hanw/p4c-bm,hanw/p4c-bm,ops-p4/ops-p4c,hanw/p4c-bm,p4lang/p4c-bm