py/emitnative: Add support for using setjmp with native emitter.

To enable this feature the N_NLR_SETJMP macro should be set to 1 before
including py/emitnative.c.

py/runtime0.h

@@ -201,6 +201,7 @@ typedef enum {
     MP_F_SMALL_INT_FLOOR_DIVIDE,
     MP_F_SMALL_INT_MODULO,
     MP_F_NATIVE_YIELD_FROM,
+    MP_F_SETJMP,
     MP_F_NUMBER_OF,
 } mp_fun_kind_t;