LSTAR - change the byte addressed by a charp pointer.

Alternate Entry Name: .LSTAR

B:
   char = lstar( char_pointer, char );

/* C users use subscripting */

char_pointer: is a character pointer (charp) as returned by the B library function CHARP.
char: is a word containing the replacement character in its lowest nine bits.

LSTAR puts "char" in the place of the nine-bit character addressed by "char_pointer". LSTAR returns the replacement character "char" as its value.

LSTAR is analogous to the more traditional B library function LCHAR, but requires only two arguments instead of three.