* threads.c (s_scm_lock_mutex): Don't declare msg in middle of

* threads.c (s_scm_lock_mutex): Don't declare msg in middle of
code.

* gc.c (s_scm_gc_live_object_stats): Don't declare alist in middle
of code.

* gc-card.c (scm_i_card_statistics): Don't declare tag in middle
of code.
(scm_i_card_statistics): Add block for declarations of tag_as_scm
and current.