[Lanai] Remove dead functions from LanaiRegisterInfo

[asb]

Summary

getEHExceptionRegister and getEHHandlerRegister are unused and were removed from most backends in rL192099. This patch removes them from Lanai.

[jpienaar]

Looks good, thanks!

lib/Target/Lanai/LanaiRegisterInfo.h

void eliminateFrameIndex(MachineBasicBlock::iterator II, int SPAdj,
                            RegScavenger *RS = nullptr) const override;
 
   // Debug information queries.
   unsigned getRARegister() const;
   unsigned getFrameRegister(const MachineFunction &MF) const override;
   unsigned getBaseRegister() const;
   bool hasBasePointer(const MachineFunction &MF) const;
 
-  // Exception handling queries.
-  unsigned getEHExceptionRegister() const;
-  unsigned getEHHandlerRegister() const;
   int getDwarfRegNum(unsigned RegNum, bool IsEH) const;
 };
 
 } // end namespace llvm
 
 #endif // LLVM_LIB_TARGET_LANAI_LANAIREGISTERINFO_H

lib/Target/Lanai/LanaiRegisterInfo.cpp

 
 unsigned
 LanaiRegisterInfo::getFrameRegister(const MachineFunction & /*MF*/) const {
   return Lanai::FP;
 }
 
 unsigned LanaiRegisterInfo::getBaseRegister() const { return Lanai::R14; }
 
-unsigned LanaiRegisterInfo::getEHExceptionRegister() const {
-  llvm_unreachable("no exception support");
-  return 0;
-}
-
-unsigned LanaiRegisterInfo::getEHHandlerRegister() const {
-  llvm_unreachable("no exception support");
-  return 0;
-}
-
 const uint32_t *
 LanaiRegisterInfo::getCallPreservedMask(const MachineFunction & /*MF*/,
                                         CallingConv::ID /*CC*/) const {
   return CSR_RegMask;
 }