[DebugInfo] Add CIE::getAugmentationData() and FDE::getCIEPointer()

[benmxwl-arm]

Summary

Public getters are provided for other similar members of both the CIE
and FDE, these fields are also displayed by the llvm-drawfdump tool,
so it seems like not exposing them was likely an oversight.

These are needed for tools based on LLVM that need access to all the
parsed DWARF data.

[keith.walker.arm]

This small change LGTM,

llvm/include/llvm/DebugInfo/DWARF/DWARFDebugFrame.h

public:
   int64_t getDataAlignmentFactor() const { return DataAlignmentFactor; }
   uint8_t getVersion() const { return Version; }
   uint64_t getReturnAddressRegister() const { return ReturnAddressRegister; }
   std::optional<uint64_t> getPersonalityAddress() const { return Personality; }
   std::optional<uint32_t> getPersonalityEncoding() const {
     return PersonalityEnc;
   }
 
+  StringRef getAugmentationData() const { return AugmentationData; }
+
   uint32_t getFDEPointerEncoding() const { return FDEPointerEncoding; }
 
   uint32_t getLSDAPointerEncoding() const { return LSDAPointerEncoding; }
 
   void dump(raw_ostream &OS, DIDumpOptions DumpOpts) const override;
 
 private:
   /// The following fields are defined in section 6.4.1 of the DWARF standard v4
FDE(bool IsDWARF64, uint64_t Offset, uint64_t Length, uint64_t CIEPointer,
                    Cie ? Cie->getCodeAlignmentFactor() : 0,
                    Cie ? Cie->getDataAlignmentFactor() : 0, Arch),
         CIEPointer(CIEPointer), InitialLocation(InitialLocation),
         AddressRange(AddressRange), LinkedCIE(Cie), LSDAAddress(LSDAAddress) {}
 
   ~FDE() override = default;
 
   const CIE *getLinkedCIE() const { return LinkedCIE; }
+  uint64_t getCIEPointer() const { return CIEPointer; }
   uint64_t getInitialLocation() const { return InitialLocation; }
   uint64_t getAddressRange() const { return AddressRange; }
   std::optional<uint64_t> getLSDAAddress() const { return LSDAAddress; }
 
   void dump(raw_ostream &OS, DIDumpOptions DumpOpts) const override;
 
   static bool classof(const FrameEntry *FE) { return FE->getKind() == FK_FDE; }