[NFC][MC][AVR] Rearrange decode functions in AVR disassembler (#155013)

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.

Author: jurahul

llvm/lib/Target/AVR/Disassembler/AVRDisassembler.cpp

@@ -91,56 +91,6 @@ static DecodeStatus DecodeLD8RegisterClass(MCInst &Inst, unsigned RegNo,
   return MCDisassembler::Success;
 }
 
-static DecodeStatus decodeFIOARr(MCInst &Inst, unsigned Insn, uint64_t Address,
-                                 const MCDisassembler *Decoder);
-
-static DecodeStatus decodeFIORdA(MCInst &Inst, unsigned Insn, uint64_t Address,
-                                 const MCDisassembler *Decoder);
-
-static DecodeStatus decodeFIOBIT(MCInst &Inst, unsigned Insn, uint64_t Address,
-                                 const MCDisassembler *Decoder);
-
-static DecodeStatus decodeCallTarget(MCInst &Inst, unsigned Insn,
-                                     uint64_t Address,
-                                     const MCDisassembler *Decoder);
-
-static DecodeStatus decodeFRd(MCInst &Inst, unsigned Insn, uint64_t Address,
-                              const MCDisassembler *Decoder);
-
-static DecodeStatus decodeFLPMX(MCInst &Inst, unsigned Insn, uint64_t Address,
-                                const MCDisassembler *Decoder);
-
-static DecodeStatus decodeFFMULRdRr(MCInst &Inst, unsigned Insn,
-                                    uint64_t Address,
-                                    const MCDisassembler *Decoder);
-
-static DecodeStatus decodeFMOVWRdRr(MCInst &Inst, unsigned Insn,
-                                    uint64_t Address,
-                                    const MCDisassembler *Decoder);
-
-static DecodeStatus decodeFWRdK(MCInst &Inst, unsigned Insn, uint64_t Address,
-                                const MCDisassembler *Decoder);
-
-static DecodeStatus decodeFMUL2RdRr(MCInst &Inst, unsigned Insn,
-                                    uint64_t Address,
-                                    const MCDisassembler *Decoder);
-
-static DecodeStatus decodeMemri(MCInst &Inst, unsigned Insn, uint64_t Address,
-                                const MCDisassembler *Decoder);
-
-static DecodeStatus decodeFBRk(MCInst &Inst, unsigned Insn, uint64_t Address,
-                               const MCDisassembler *Decoder);
-
-static DecodeStatus decodeCondBranch(MCInst &Inst, unsigned Insn,
-                                     uint64_t Address,
-                                     const MCDisassembler *Decoder);
-
-static DecodeStatus decodeLoadStore(MCInst &Inst, unsigned Insn,
-                                    uint64_t Address,
-                                    const MCDisassembler *Decoder);
-
-#include "AVRGenDisassemblerTables.inc"
-
 static DecodeStatus decodeFIOARr(MCInst &Inst, unsigned Insn, uint64_t Address,
                                  const MCDisassembler *Decoder) {
   unsigned addr = 0;
@@ -435,6 +385,8 @@ static DecodeStatus decodeLoadStore(MCInst &Inst, unsigned Insn,
   return MCDisassembler::Success;
 }
 
+#include "AVRGenDisassemblerTables.inc"
+
 static DecodeStatus readInstruction16(ArrayRef<uint8_t> Bytes, uint64_t Address,
                                       uint64_t &Size, uint32_t &Insn) {
   if (Bytes.size() < 2) {