struct lrecord_header size

Fow now, on linux x86 at least (which probably means on all compiles with gcc on 32bits computers I'm afraid), the struct lrecord_header size is 8 bytes. struct lrecord_header { /* index into lrecord_implementations_table[] */ unsigned char type; struct { /* 1 if the object is marked during GC. */ unsigned mark :1; /* 1 if the object resides in read-only space */ unsigned c_readonly : 1; /* 1 if the object is readonly from lisp */ unsigned lisp_readonly : 1; } flags; }; We may want someday to integrate the type into the flags struct to go back to 4 bytes _or_ change the unsigned char to int (which may make the code faster, but probably only when using error checking).