[LoongArch] Include missing header files after D119244

[MaskRay]

Thanks!

[SixWeining]

Thanks for your review @MaskRay. I have no commit acess and could you help to land this patch with author "Lu Weining <[e-mail]>"?

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchAsmBackend.h

 
 #ifndef LLVM_LIB_TARGET_LOONGARCH_MCTARGETDESC_LOONGARCHASMBACKEND_H
 #define LLVM_LIB_TARGET_LOONGARCH_MCTARGETDESC_LOONGARCHASMBACKEND_H
 
 #include "MCTargetDesc/LoongArchBaseInfo.h"
 #include "MCTargetDesc/LoongArchMCTargetDesc.h"
 #include "llvm/MC/MCAsmBackend.h"
 #include "llvm/MC/MCFixupKindInfo.h"
+#include "llvm/MC/MCSubtargetInfo.h"
 
 namespace llvm {
 
 class LoongArchAsmBackend : public MCAsmBackend {
   const MCSubtargetInfo &STI;
   uint8_t OSABI;
   bool Is64Bit;
 

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchMCCodeEmitter.cpp

 //===----------------------------------------------------------------------===//
 
 #include "MCTargetDesc/LoongArchBaseInfo.h"
 #include "MCTargetDesc/LoongArchMCTargetDesc.h"
 #include "llvm/MC/MCCodeEmitter.h"
 #include "llvm/MC/MCContext.h"
 #include "llvm/MC/MCInstBuilder.h"
 #include "llvm/MC/MCInstrInfo.h"
+#include "llvm/MC/MCRegisterInfo.h"
 #include "llvm/Support/EndianStream.h"
 
 using namespace llvm;
 
 #define DEBUG_TYPE "mccodeemitter"
 
 namespace {
 class LoongArchMCCodeEmitter : public MCCodeEmitter {

llvm/lib/Target/LoongArch/MCTargetDesc/LoongArchMCTargetDesc.cpp

 #include "LoongArchMCTargetDesc.h"
 #include "LoongArchBaseInfo.h"
 #include "LoongArchInstPrinter.h"
 #include "LoongArchMCAsmInfo.h"
 #include "TargetInfo/LoongArchTargetInfo.h"
 #include "llvm/MC/MCAsmInfo.h"
 #include "llvm/MC/MCDwarf.h"
 #include "llvm/MC/MCInstrInfo.h"
+#include "llvm/MC/MCRegisterInfo.h"
 #include "llvm/MC/MCSubtargetInfo.h"
 #include "llvm/MC/TargetRegistry.h"
 #include "llvm/Support/Compiler.h"
 
 #define GET_INSTRINFO_MC_DESC
 #include "LoongArchGenInstrInfo.inc"
 
 #define GET_REGINFO_MC_DESC