* files.c (scm_sys_delete_file): Moved to filesys.c.

* files.c (scm_sys_delete_file): Moved to filesys.c.
File is now empty; deleted.
* files.h: Deleted.
* filesys.c: scm_sys_delete_file is now here.  Remove
#if's; they seem to rely on remnants of an old portability
regimen.  If the problems come up again, solve them properly,
using autoconf.  Specifically: Don't test M_SYSV, and #define
remove to be unlink if it's #defined; don't use remove just
because HAVE_STDC_HEADERS is #defined.
* filesys.h: Add declarations for scm_sys_delete_file.
* Makefile.in (libobjs, inner_h_files, c_files, gen_c_files): Omit
files.o, files.h, files.c, and files.x.
* init.c: Don't #include "files.h", and don't call scm_init_files.