cmd/internal/obj/arm64: support logical instructions targeting RSP
Logical instructions can have RSP as its destination. Support it.
Note that the two-operand form, like "AND $1, RSP", which is
equivalent to the three-operand form "AND $1, RSP, RSP", is
invalid, because the source register is not allowed to be RSP.
Also note that instructions that set the conditional flags, like
ANDS, cannot target RSP. Because of this, we split out the optab
entries of AND et al. and ANDS et al.
Merge the optab entries of BIC et al. to AND et al., because they
are same.