Add ReadonlyOp to MemberKey for member operation bytecodes 2/2
Summary:
Add ReadonlyOp immediate to bytecodes in MemberKey argument.
```
- {SetM, QueryM, IncDecM, SetOpM, Dim}
```
- Since we pack it into the MemberKey, the `UnsetM` bytecode contains a `ReadonlyOp` as well.
- ReadonlyOp -> ReadOnlyOp per nit on prev diff and precedent of Pascal Case for other immediates.
ReadonlyOp can be `{ReadOnly, Mutable, Any}`
Emit dummy value `Any` for now from HackC.
Reviewed By: ricklavoie
Differential Revision:
D26389393
fbshipit-source-id:
9f335e6c89a9a9ea52b90c678e65853d6e3d14eb