Rearrange decode functions to be before including the generated disassembler code and eliminate forward declarations for most of them. This is possible because `fieldFromInstruction` is now in MCDecoder.h and not in the generated disassembler code.
Rearrange decode functions to be before including the generated disassembler code and eliminate forward declarations for most of them. This is possible because `fieldFromInstruction` is now in MCDecoder.h and not in the generated disassembler code.