[ARM] GlobalISel: Support SP in regbankselect

We used to hit an unreachable in getRegBankFromRegClass when dealing with the
stack pointer. This commit adds support for the GPRsp reg class.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@297621 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed