[AArch64] Lower SHL_PARTS, SRA_PARTS and SRL_PARTS

Lower SHL_PARTS, SRA_PARTS and SRL_PARTS to perform 128-bit integer shift

Patch by GuanHong Liu.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204940 91177308-0d34-0410-b5e6-96231b3b80d8