Set general global handle for extension registration work

* When calling the register() function there is no frame or globals, so we need
  to set an internal handle external to that.
* This means functions that get wrapped know that there's a global handler for
  exceptions, which just prints to the log. Otherwise they think they're running
  synchronously and write to an invalid exception handling object.

qrenderdoc/Code/pyrenderdoc/function_conversion.h

@@ -28,6 +28,7 @@
 
 // this is defined elsewhere for managing the opaque global_handle object
 extern "C" PyThreadState *GetExecutingThreadState(PyObject *global_handle);
+extern "C" PyObject *GetCurrentGlobalHandle();
 extern "C" void HandleException(PyObject *global_handle);
 extern "C" bool IsThreadBlocking(PyObject *global_handle);
 extern "C" void SetThreadBlocking(PyObject *global_handle, bool block);
@@ -249,6 +250,9 @@ funcType ConvertFunc(const char *funcname, PyObject *func, ExceptionHandling &ex
     }
   }
 
+  if(!global_internal_handle)
+    global_internal_handle = GetCurrentGlobalHandle();
+
   // create a copy that will keep the function object alive as long as the lambda is
   PyObjectRefCounter funcptr(func);