[PATCH] [AArch64]Fix the problems that can't select mul/add/sub of v1i8/v1i16/v1i32 types

[Tim Northover]

  Hi Hao,

  This looks good, though I have to say I'm really starting to doubt the wisdom of adding v1iN as valid types. We're adding so much boiler-plate to cope with the extra operations. Oh well, a problem for another day.

  Cheers.

  Tim.

http://llvm-reviews.chandlerc.com/D2735