* dlltool.c (prefix_encode): New function. Encode temp file prefix from pid.

* dlltool.c (prefix_encode): New function.  Encode temp file prefix from pid.
(dlltmp): Pass address of pointer being alloced or suffer neverending mallocs.
(make_one_lib_file): Allocate enough space for new longer stub names.
(gen_lib_file): Ditto.
(main): Generate the temp file prefix from the pid if prefix was not specified
on the command line.