[DebugInfo] Remove a misleading comment for llvm::dwarf::FDE.

[ikudrin]

Summary

The comment described a linked CIE to be acquired lazily. That is not true and looks like it was never true.

Notes. The comment was initially added in https://reviews.llvm.org/rGfd08bc195b36b2262f9ee4b283eef44b0520ebed and was moved into its current location in https://reviews.llvm.org/D43313.

[jhenderson]

LGTM, but it might be worth waiting for somebody else with more familiarity with the debug frame code to confirm it makes sense.

[ikudrin]

It looks like nobody else is willing to comment, so I am applying this.

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

private:
   const uint32_t LSDAPointerEncoding;
   const Optional<uint64_t> Personality;
   const Optional<uint32_t> PersonalityEnc;
 };
 
 /// DWARF Frame Description Entry (FDE)
 class FDE : public FrameEntry {
 public:
-  // Each FDE has a CIE it's "linked to". Our FDE contains is constructed with
-  // an offset to the CIE (provided by parsing the FDE header). The CIE itself
-  // is obtained lazily once it's actually required.
   FDE(uint64_t Offset, uint64_t Length, int64_t LinkedCIEOffset,
       uint64_t InitialLocation, uint64_t AddressRange, CIE *Cie,
       Optional<uint64_t> LSDAAddress, Triple::ArchType Arch)
       : FrameEntry(FK_FDE, Offset, Length,
                    Cie ? Cie->getCodeAlignmentFactor() : 0,
                    Cie ? Cie->getDataAlignmentFactor() : 0,
                    Arch),
         LinkedCIEOffset(LinkedCIEOffset), InitialLocation(InitialLocation),