Created by: joshua-warburton
This patch adds the appropriate macros, tests and codec entries to encode the following variants:
MAD <Zdn>.<Ts>, <Pg>/M, <Zm>.<Ts>, <Za>.<Ts>
MLA <Zda>.<Ts>, <Pg>/M, <Zn>.<Ts>, <Zm>.<Ts>
MLS <Zda>.<Ts>, <Pg>/M, <Zn>.<Ts>, <Zm>.<Ts>
MSB <Zdn>.<Ts>, <Pg>/M, <Zm>.<Ts>, <Za>.<Ts>
MUL <Zdn>.<Ts>, <Pg>/M, <Zdn>.<Ts>, <Zm>.<Ts>
MUL <Zdn>.<Ts>, <Zdn>.<Ts>, #<imm>
SMULH <Zdn>.<Ts>, <Pg>/M, <Zdn>.<Ts>, <Zm>.<Ts>
UMULH <Zdn>.<Ts>, <Pg>/M, <Zdn>.<Ts>, <Zm>.<Ts>
issues: #3044