We will get an assertion of 'Unknown memory constraint' when we dump
MachineOperand with constraint A.
Oops, we should have fixed it in D124431. Sorry @Jim, I didn't know it.
The order look like is low case with alphabetical, capital with alphabetical, ..
Closed as I want to use this patch to be familiar with Github workflow(https://github.com/llvm/llvm-project/pull/65292).