This patch adds the appropriate macros, tests and codec entries to encode the following variants:
FCADD <Vd>.<Ts>, <Vn>.<Ts>, <Vm>.<Ts>, <imm>
FCMLA <Vd>.<Ts>, <Vn>.<Ts>, <Vm>.<Ts>, <imm>
FCMLA <Vd>.<Ts>, <Vn>.<Ts>, <Vm>.<Tb>[<imm1>], <imm2>
Issue #2626