gc before polling

Author: qunaibit

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/cext/capi/transitions/CApiTransitions.java

@@ -409,6 +409,7 @@ public static PyCapsuleReference registerPyCapsuleDestructor(PyCapsule capsule)
 
     @TruffleBoundary
     public static void exitPollCleanup() {
+        PythonUtils.forceFullGC();
         PythonContext context = PythonContext.get(null);
         HandleContext handleContext = context.nativeContext;
         int len = handleContext.nativeStubLookup.length;