[CodeGen] Use ArrayRef instead of std::vector&. NFC.

The former lets us use SmallVectors.  Do so in ARM and AArch64.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@229925 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed