[RISCV] Add Predicate to c.lw/c.sw/c.lwsp/c.swsp InstAliases with no offset.

These are aliases that allow the immediate offset to be ommitted.
We had predicates for the RV64, RV32+F, and D versions, but
not the base versions.

I've also re-ordered them to share Predicate lines to improve
readability.