SWI-style Constraints in C

Functions:

1. static Int get_attr(USES_REGS1):

1. static Int get_attrs(USES_REGS1):

1. static Int put_attr(USES_REGS1):

1. static Int put_attrs(USES_REGS1):

1. static Int del_attr(USES_REGS1):

1. static Int del_attrs(USES_REGS1):

1. static Int swi_all_atts(USES_REGS1): : just get everything

1. static Term AllAttVars(USES_REGS1):

1. static Int all_attvars(USES_REGS1):

1. static Int is_attvar(USES_REGS1):

1. static Int attvar_bound(USES_REGS1):

1. static Int void_term(USES_REGS1):

1. static Int free_term(USES_REGS1):

1. static Int fast_unify(USES_REGS1):

1. void Yap_InitAttVarPreds(void):