aarch64: rcpc3: Add integer load/store insns

aarch64: rcpc3: Add integer load/store insns

Along with the relevant unit tests and updates to the existing
regression tests, this adds support for the following novel rcpc3
insns:

  LDIAPP <Wt1>, <Wt2>, [<Xn|SP>]
  LDIAPP <Wt1>, <Wt2>, [<Xn|SP>], #8
  LDIAPP <Xt1>, <Xt2>, [<Xn|SP>]
  LDIAPP <Xt1>, <Xt2>, [<Xn|SP>], #16

  STILP <Wt1>, <Wt2>, [<Xn|SP>]
  STILP <Wt1>, <Wt2>, [<Xn|SP>, #-8]!
  STILP <Xt1>, <Xt2>, [<Xn|SP>]
  STILP <Xt1>, <Xt2>, [<Xn|SP>, #-16]!

  LDAPR <Wt>, [<Xn|SP>], #4
  LDAPR <Xt>, [<Xn|SP>], #8

  STLR <Wt>, [<Xn|SP>, #-4]!
  STLR <Xt>, [<Xn|SP>, #-8]!