[llvm] [LLVM][DWARF] Change .debug_names abbrev to be an index (PR #81200)

[Felipe de Azevedo Piovezan via llvm-commits]

================
@@ -223,6 +225,15 @@ class Dwarf5AccelTableWriter : public AccelTableWriter {
   bool IsSplitDwarf = false;
   /// Stores the DIE offsets which are indexed by this table.
   DenseSet<OffsetAndUnitID> IndexedOffsets;
+  /// Mapping between AbbrevTag and Index.
+  std::unordered_map<uint32_t, uint32_t> AbbrevTagToIndexMap;
----------------
felipepiovezan wrote:

I think this is one of the canonical cases for a `DenseMap`

https://github.com/llvm/llvm-project/pull/81200