MARK> MAKE MARKER
MARK>
* MARK> ( -- DP-mark ) compile-only

makes room for a pointer in the dictionary to
be resolved through >RESOLVE> and does therefore
memorize that cell's address on the CS-STACK
Mostly used after >BRANCH or >?BRANCH in compiling
words like IF or ELSE 
 simulate:
   : MARK> ?COMP  HERE 0 , ;

system ordinary primitive