[AArch64] Refactor the loads and stores optimizer

Move remaining inline matching of instructions of some optimizations into
separate functions, like in the other optimizations.  Otherwise, NFC.

Differential revision: https://reviews.llvm.org/D40090

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@318335 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed