17ba194c1e
builtins. Required changes: - be careful about creeping in deallocate: it may be followed by something that is not a cut nor a proceed. - include new instruction in absmi.c: it is a merge of execute and call_cpred. - change compiler to generate execute even for C builtins. - be careful with dexecute: it may not be done if execute_op is a C builtin. - if we are in execute_cpred, the garbage collector cannot trust P: instead it must look at CP to find out the size of the current environment. The macro gc_P receives that information. - We don't need to change CP if we do a meta-call from within execute_cpred (and we in fact cannot). Check places where we do meta-calls: exec, clause in cdmgr, and lu_recorded.