Revert "Implement AArch64 vector load/store multiple N-element structure class SIMD...

Revert "Implement AArch64 vector load/store multiple N-element structure class SIMD(lselem). Including following 14 instructions: 4 ld1 insts: load multiple 1-element structure to sequential 1/2/3/4 registers. ld2/ld3/ld4: load multiple N-element structure to sequential N registers (N=2,3,4). 4 st1 insts: store multiple 1-element structure from sequential 1/2/3/4 registers. st2/st3/st4: store multiple N-element structure from sequential N registers (N = 2,3,4)."

This reverts commit r192352. It broke the build.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192354 91177308-0d34-0410-b5e6-96231b3b80d8