[NFC][MC][XCore] Rearrange decoder functions for XCore disassembler (llvm#155009)

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/XCore/Disassembler/XCoreDisassembler.cpp

@@ -74,66 +74,13 @@ static unsigned getReg(const MCDisassembler *D, unsigned RC, unsigned RegNo) {
   return *(RegInfo->getRegClass(RC).begin() + RegNo);
 }
 
-static DecodeStatus DecodeGRRegsRegisterClass(MCInst &Inst, unsigned RegNo,
-                                              uint64_t Address,
-                                              const MCDisassembler *Decoder);
-
-static DecodeStatus DecodeRRegsRegisterClass(MCInst &Inst, unsigned RegNo,
-                                             uint64_t Address,
-                                             const MCDisassembler *Decoder);
-
-static DecodeStatus DecodeBitpOperand(MCInst &Inst, unsigned Val,
-                                      uint64_t Address,
-                                      const MCDisassembler *Decoder);
-
-static DecodeStatus DecodeNegImmOperand(MCInst &Inst, unsigned Val,
-                                        uint64_t Address,
-                                        const MCDisassembler *Decoder);
-
-static DecodeStatus Decode2RInstruction(MCInst &Inst, unsigned Insn,
-                                        uint64_t Address,
-                                        const MCDisassembler *Decoder);
-
-static DecodeStatus Decode2RImmInstruction(MCInst &Inst, unsigned Insn,
-                                           uint64_t Address,
-                                           const MCDisassembler *Decoder);
-
-static DecodeStatus DecodeR2RInstruction(MCInst &Inst, unsigned Insn,
-                                         uint64_t Address,
-                                         const MCDisassembler *Decoder);
-
-static DecodeStatus Decode2RSrcDstInstruction(MCInst &Inst, unsigned Insn,
-                                              uint64_t Address,
-                                              const MCDisassembler *Decoder);
-
-static DecodeStatus DecodeRUSInstruction(MCInst &Inst, unsigned Insn,
-                                         uint64_t Address,
-                                         const MCDisassembler *Decoder);
-
-static DecodeStatus DecodeRUSBitpInstruction(MCInst &Inst, unsigned Insn,
-                                             uint64_t Address,
-                                             const MCDisassembler *Decoder);
-
-static DecodeStatus
-DecodeRUSSrcDstBitpInstruction(MCInst &Inst, unsigned Insn, uint64_t Address,
-                               const MCDisassembler *Decoder);
-
-static DecodeStatus DecodeL2RInstruction(MCInst &Inst, unsigned Insn,
-                                         uint64_t Address,
-                                         const MCDisassembler *Decoder);
-
-static DecodeStatus DecodeLR2RInstruction(MCInst &Inst, unsigned Insn,
-                                          uint64_t Address,
-                                          const MCDisassembler *Decoder);
-
 static DecodeStatus Decode3RInstruction(MCInst &Inst, unsigned Insn,
                                         uint64_t Address,
                                         const MCDisassembler *Decoder);
 
 static DecodeStatus Decode3RImmInstruction(MCInst &Inst, unsigned Insn,
                                            uint64_t Address,
                                            const MCDisassembler *Decoder);
-
 static DecodeStatus Decode2RUSInstruction(MCInst &Inst, unsigned Insn,
                                           uint64_t Address,
                                           const MCDisassembler *Decoder);
@@ -158,24 +105,6 @@ static DecodeStatus DecodeL2RUSBitpInstruction(MCInst &Inst, unsigned Insn,
                                                uint64_t Address,
                                                const MCDisassembler *Decoder);
 
-static DecodeStatus DecodeL6RInstruction(MCInst &Inst, unsigned Insn,
-                                         uint64_t Address,
-                                         const MCDisassembler *Decoder);
-
-static DecodeStatus DecodeL5RInstruction(MCInst &Inst, unsigned Insn,
-                                         uint64_t Address,
-                                         const MCDisassembler *Decoder);
-
-static DecodeStatus DecodeL4RSrcDstInstruction(MCInst &Inst, unsigned Insn,
-                                               uint64_t Address,
-                                               const MCDisassembler *Decoder);
-
-static DecodeStatus
-DecodeL4RSrcDstSrcDstInstruction(MCInst &Inst, unsigned Insn, uint64_t Address,
-                                 const MCDisassembler *Decoder);
-
-#include "XCoreGenDisassemblerTables.inc"
-
 static DecodeStatus DecodeGRRegsRegisterClass(MCInst &Inst, unsigned RegNo,
                                               uint64_t Address,
                                               const MCDisassembler *Decoder) {
@@ -713,6 +642,8 @@ DecodeL4RSrcDstSrcDstInstruction(MCInst &Inst, unsigned Insn, uint64_t Address,
   return S;
 }
 
+#include "XCoreGenDisassemblerTables.inc"
+
 MCDisassembler::DecodeStatus
 XCoreDisassembler::getInstruction(MCInst &instr, uint64_t &Size,
                                   ArrayRef<uint8_t> Bytes, uint64_t Address,