ARM refactor more NEON VLD/VST instructions to use composite physregs

Register pair VLD1/VLD2 all-lanes instructions. Kill off more of the
pseudos as a result.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152150 91177308-0d34-0410-b5e6-96231b3b80d8
9 files changed