[AArch64][AsmParser] Add support for parsing shift/extend operands with symbols.

Differential Revision: https://reviews.llvm.org/D27953

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@290609 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed