py/objgenerator: Move defn of mp_const_GeneratorExit_obj here.

Because the mp_obj_exception_t type is now globally available.

py/objexcept.c

@@ -100,11 +100,6 @@ mp_obj_t mp_alloc_emergency_exception_buf(mp_obj_t size_in) {
 #endif
 #endif  // MICROPY_ENABLE_EMERGENCY_EXCEPTION_BUF
 
-// Instance of GeneratorExit exception - needed by generator.close()
-// This would belong to objgenerator.c, but to keep mp_obj_exception_t
-// definition module-private so far, have it here.
-const mp_obj_exception_t mp_const_GeneratorExit_obj = {{&mp_type_GeneratorExit}, 0, 0, NULL, (mp_obj_tuple_t*)&mp_const_empty_tuple_obj};
-
 void mp_obj_exception_print(const mp_print_t *print, mp_obj_t o_in, mp_print_kind_t kind) {
     mp_obj_exception_t *o = MP_OBJ_TO_PTR(o_in);
     mp_print_kind_t k = kind & ~PRINT_EXC_SUBCLASS;

py/objgenerator.c

@@ -34,6 +34,9 @@
 #include "py/objfun.h"
 #include "py/stackctrl.h"
 
+// Instance of GeneratorExit exception - needed by generator.close()
+const mp_obj_exception_t mp_const_GeneratorExit_obj = {{&mp_type_GeneratorExit}, 0, 0, NULL, (mp_obj_tuple_t*)&mp_const_empty_tuple_obj};
+
 /******************************************************************************/
 /* generator wrapper                                                          */