the code for def rules now uses proper graph update to preserve lazyness

src/runtime/c/pgf/data.h

@@ -121,11 +121,13 @@ typedef enum {
   PGF_INSTR_SET_VALUE,
   PGF_INSTR_SET_ARG_VAR,
   PGF_INSTR_SET_FREE_VAR,
+  PGF_INSTR_SET_PAD,
   PGF_INSTR_PUSH_VALUE,
   PGF_INSTR_PUSH_ARG_VAR,
   PGF_INSTR_PUSH_FREE_VAR,
   PGF_INSTR_TAIL_CALL,
   PGF_INSTR_FAIL,
+  PGF_INSTR_UPDATE,
   PGF_INSTR_RET
 } PgfInstruction;