If a code object is compiled with nested scopes, define the CO_NESTED flag.
Add PyEval_GetNestedScopes() which returns a non-zero value if the
code for the current interpreter frame has CO_NESTED defined.
diff --git a/Include/compile.h b/Include/compile.h
index deb8ee8..e60af59 100644
--- a/Include/compile.h
+++ b/Include/compile.h
@@ -32,6 +32,7 @@
#define CO_NEWLOCALS 0x0002
#define CO_VARARGS 0x0004
#define CO_VARKEYWORDS 0x0008
+#define CO_NESTED 0x0010
extern DL_IMPORT(PyTypeObject) PyCode_Type;