MIR: Fix parsing of stack object references in MachineMemOperands

The MachineMemOperand parser lacked the code to handle %stack.X
references (%fixed-stack.X was working).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@272082 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed