[llvm] [LLVM][DWARF] Fix for memory leak (PR #81828)

[Alexander Yermolovich via llvm-commits]

================
@@ -251,7 +251,10 @@ class Dwarf5AccelTableWriter : public AccelTableWriter {
           const DWARF5AccelTableData &)>
           getIndexForEntry,
       bool IsSplitDwarf);
-
+  ~Dwarf5AccelTableWriter() {
+    for (DebugNamesAbbrev *Abbrev : AbbreviationsVector)
+      Abbrev->~DebugNamesAbbrev();
+  }
----------------
ayermolo wrote:

We can.... I don't really have a strong opinion on this. 
It will look something like

```
std::unique_ptr<DebugNamesAbbrev> NewAbbrev =
            std::make_unique<DebugNamesAbbrev>(std::move(Abbrev));
        NewAbbrev->setNumber(AbbreviationsVector.size() + 1);
        AbbreviationsVector.push_back(std::move(NewAbbrev));
        AbbreviationsSet.InsertNode(AbbreviationsVector.back().get(), InsertPos);
        Value->setAbbrevNumber(AbbreviationsVector.back()->getNumber());
```

Couple reasons for leaving it like this
1) Bumpptr allocator seems to be a more standard way of dong things, although it can lead to situations like this.
2) This is also how .debug_abbrev handles it. Since we are going for convergence at some point.

https://github.com/llvm/llvm-project/pull/81828