lldb wants to serialize a FILE, so pass it the header with the size now that it's an opaque
struct.

diff --git a/lldb/source/API/SBReproducerPrivate.h b/lldb/source/API/SBReproducerPrivate.h
index 02ac31c2ad89..0ec65e63fffe 100644
--- a/lldb/source/API/SBReproducerPrivate.h
+++ b/lldb/source/API/SBReproducerPrivate.h
@@ -19,6 +19,7 @@
 #include "lldb/Utility/ReproducerProvider.h"
 
 #include "llvm/ADT/DenseMap.h"
+#include <bits/struct_file.h>
 
 #define LLDB_GET_INSTRUMENTATION_DATA()                                        \
   lldb_private::repro::InstrumentationData::Instance()