[AArch64] Refactor the scheduling predicates (2/3) (NFC)

Refactor the scheduling predicates based on `MCInstPredicate`.  In this
case, `AArch64InstrInfo::hasShiftedReg()`.

Differential revision: https://reviews.llvm.org/D54820

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@347598 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed