[lldb/DWARF] Remove DWARFDebugRangesBase abstract class

now that we use llvm to parse debug_rnglists, this abstraction is not
useful.

Author: labath

lldb/source/Plugins/SymbolFile/DWARF/DWARFDebugRanges.h

@@ -17,22 +17,13 @@ namespace lldb_private {
 class DWARFContext;
 }
 
-class DWARFDebugRangesBase {
-public:
-  virtual ~DWARFDebugRangesBase(){};
-
-  virtual void Extract(lldb_private::DWARFContext &context) = 0;
-  virtual bool FindRanges(const DWARFUnit *cu, dw_offset_t debug_ranges_offset,
-                          DWARFRangeList &range_list) const = 0;
-};
-
-class DWARFDebugRanges final : public DWARFDebugRangesBase {
+class DWARFDebugRanges {
 public:
   DWARFDebugRanges();
 
-  void Extract(lldb_private::DWARFContext &context) override;
+  void Extract(lldb_private::DWARFContext &context);
   bool FindRanges(const DWARFUnit *cu, dw_offset_t debug_ranges_offset,
-                  DWARFRangeList &range_list) const override;
+                  DWARFRangeList &range_list) const;
 
   static void Dump(lldb_private::Stream &s,
                    const lldb_private::DWARFDataExtractor &debug_ranges_data,

lldb/source/Plugins/SymbolFile/DWARF/DWARFUnit.cpp

@@ -883,7 +883,7 @@ uint32_t DWARFUnit::GetHeaderByteSize() const {
 llvm::Expected<DWARFRangeList>
 DWARFUnit::FindRnglistFromOffset(dw_offset_t offset) {
   if (GetVersion() <= 4) {
-    const DWARFDebugRangesBase *debug_ranges = m_dwarf.GetDebugRanges();
+    const DWARFDebugRanges *debug_ranges = m_dwarf.GetDebugRanges();
     if (!debug_ranges)
       return llvm::make_error<llvm::object::GenericBinaryError>(
           "No debug_ranges section");