[llvm] [DWARF] Speedup .gdb_index dumping (PR #151806)

[David Blaikie via llvm-commits]

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@@ -60,6 +61,24 @@ void DWARFGdbIndex::dumpSymbolTable(raw_ostream &OS) const {
                ", filled slots:",
                SymbolTableOffset, (uint64_t)SymbolTable.size())
      << '\n';
+
+  std::unordered_map<uint32_t, decltype(ConstantPoolVectors)::const_iterator>
+      CuVectorMap{};
+  CuVectorMap.reserve(ConstantPoolVectors.size());
+  const auto FindCuVector =
+      [&CuVectorMap, notFound = ConstantPoolVectors.end()](uint32_t vecOffset) {
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dwblaikie wrote:

I probably wouldn't bother separately capturing things like this in a locally scoped non-erased functor. Probably just use `[&]` and `return ConstantPoolVectors.end();` in the fail-case.

https://github.com/llvm/llvm-project/pull/151806