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

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D99731

Author: jankratochvil

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

@@ -170,7 +170,8 @@ template <typename DWARFListType> class DWARFListTableBase {
   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(); }
@@ -275,7 +276,7 @@ void DWARFListTableBase<DWARFListType>::dump(
 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())