Try not to cause a MemoryError when raising an exception during nterrupt handling.

Step 1 fixes #732

1 files changed, 1 insertions, 0 deletions

diff --git a/py/gc.h b/py/gc.h
index cea368f48..3b3b7dbb5 100644
--- a/py/gc.h
+++ b/py/gc.h
@@ -30,6 +30,7 @@ void gc_init(void *start, void *end);
 // They can be used to prevent the GC from allocating/freeing.
 void gc_lock(void);
 void gc_unlock(void);
+bool gc_is_locked(void);
 
 // A given port must implement gc_collect by using the other collect functions.
 void gc_collect(void);