[llvm] [Minidump] Support multiple exceptions in a minidump (PR #107319)

[Pavel Labath via llvm-commits]

================
@@ -216,8 +219,68 @@ class MinidumpFile : public Binary {
     bool IsEnd;
   };
 
+  class ExceptionStreamsIterator {
+  public:
+    static ExceptionStreamsIterator begin(ArrayRef<minidump::Directory> Streams,
+                                          const MinidumpFile *File) {
+      return ExceptionStreamsIterator(Streams, File);
+    }
+
+    static ExceptionStreamsIterator end() { return ExceptionStreamsIterator(); }
+
+    bool operator==(const ExceptionStreamsIterator &R) const {
+      return Streams.empty() && R.Streams.empty();
----------------
labath wrote:

```suggestion
      return Streams.begin() == R.Streams.begin();
```
So that it also works for non-end iterators. (You just need to be careful to construct the end iterator with an `[end, end)` ArrayRef instead of `[null, null)`

https://github.com/llvm/llvm-project/pull/107319