[AArch64][RegisterBankInfo] Provide alternative mappings for 64-bit load

This allows RegBankSelect in greedy mode to get rid some of the cross
register bank copies when loads are involved in the chain of
computation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@284097 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed