[nfc] [llvm] Make DWARFListTableBase::findList const

[jankratochvil]

Summary

Needed for D99653, it looks harmless to me.

[dblaikie]

If it compiles (looks like it should - don't see any caching in member variables, etc), seems fine by me.

[jankratochvil]

OK, thanks, I just wasn't sure with obvious commits for the LLVM part.

llvm/include/llvm/DebugInfo/DWARF/DWARFListTable.h

public:
   /// Extract the table header and the array of offsets.
   Error extractHeaderAndOffsets(DWARFDataExtractor Data, uint64_t *OffsetPtr) {
     return Header.extract(Data, OffsetPtr);
   }
   /// Extract an entire table, including all list entries.
   Error extract(DWARFDataExtractor Data, uint64_t *OffsetPtr);
   /// Look up a list based on a given offset. Extract it and enter it into the
   /// list map if necessary.
-  Expected<DWARFListType> findList(DWARFDataExtractor Data, uint64_t Offset);
+  Expected<DWARFListType> findList(DWARFDataExtractor Data,
+                                   uint64_t Offset) const;
 
   uint64_t getHeaderOffset() const { return Header.getHeaderOffset(); }
   uint8_t getAddrSize() const { return Header.getAddrSize(); }
   dwarf::DwarfFormat getFormat() const { return Header.getFormat(); }
 
   void dump(DWARFDataExtractor Data, raw_ostream &OS,
             llvm::function_ref<Optional<object::SectionedAddress>(uint32_t)>
                 LookupPooledAddress,
for (const auto &List : ListMap)
     for (const auto &Entry : List.second.getEntries())
       Entry.dump(OS, getAddrSize(), MaxEncodingStringLength, CurrentBase,
                  DumpOpts, LookupPooledAddress);
 }
 
 template <typename DWARFListType>
 Expected<DWARFListType>
 DWARFListTableBase<DWARFListType>::findList(DWARFDataExtractor Data,
-                                            uint64_t Offset) {
+                                            uint64_t Offset) const {
   // Extract the list from the section and enter it into the list map.
   DWARFListType List;
   if (Header.length())
     Data = DWARFDataExtractor(Data, getHeaderOffset() + Header.length());
   if (Error E =
           List.extract(Data, Header.length() ? getHeaderOffset() : 0, &Offset,
                        Header.getSectionName(), Header.getListTypeString()))
     return std::move(E);
   return List;
 }
 
 } // end namespace llvm
 
 #endif // LLVM_DEBUGINFO_DWARF_DWARFLISTTABLE_H