Fixed warnings due to unused stuff.

Fixed warnings due to unused stuff.

* libguile/gc.c (scm_cells_allocated, scm_last_cells_allocated,
  scm_gc_cells_collected, scm_gc_cells_collected_1,
  scm_gc_malloc_collected, scm_gc_time_taken, t_before_gc,
  scm_gc_mark_time_taken, scm_gc_times, scm_gc_cells_swept,
  scm_gc_cells_marked_acc, scm_gc_cells_swept_acc,
  scm_gc_cell_yield_percentage, scm_gc_malloc_yield_percentage):
  Removed.

* libguile/gc.h: Updated accordingly.

* libguile/gdbint.c (port_mark_p, stream_mark_p, string_mark_p,
  unmark_port, remark_port): Removed.

git-archimport-id: lcourtes@laas.fr--2006-libre/guile-core--boehm-gc--0--patch-4