Make NEON ld/st pseudo instruction classes take the instruction itinerary as

an argument, so that we can distinguish instructions with the same register
classes but different numbers of registers (e.g., vld3 and vld4).  Fix some
of the non-pseudo NEON ld/st instruction itineraries to reflect the number
of registers loaded or stored, not just the opcode name.

llvm-svn: 113854