Output: Fix output of forward-declared classes

When adding a dump node for a class, use the class definition, if
available, instead of the canonical declaration.  They may not be the
same when a class is forward-declared before it is defined.  We need to
use the definition to get all members.

1 files changed, 8 insertions, 0 deletions

diff --git a/test/input/Class-forward.cxx b/test/input/Class-forward.cxx
new file mode 100644
index 0000000..38374b6
--- /dev/null
+++ b/test/input/Class-forward.cxx
@@ -0,0 +1,8 @@
+class start;
+class start {
+public:
+  start();
+  start(start const&);
+  start& operator=(start const&);
+  ~start();
+};