libast: cleanup: remove unused astcopy function

It has been unused in the entire history of the ast-open-archive
repo as well as ours.

Also stop generating the public ast_mmap.h header, which is also
unused (it's a copy of FEATURE/mmap which is used internally by
libast).

src/lib/libast/Mamfile

@@ -152,10 +152,6 @@ make install virtual
 		prev FEATURE/lib
 		exec - cp -f %{<} %{@}
 	done
-	make ast_mmap.h
-		prev FEATURE/mmap
-		exec - cp -f %{<} %{@}
-	done
 	make ast_fs.h
 		prev FEATURE/fs
 		exec - cp -f %{<} %{@}
@@ -4295,15 +4291,6 @@ make install virtual
 			exec - compile %{<}
 		done
 
-		make astcopy.o
-			make port/astcopy.c
-				prev include/ls.h
-				prev ast_mmap.h
-				prev include/ast.h
-			done
-			exec - compile %{<}
-		done
-
 		make astconf.o
 			make port/astconf.c
 				prev FEATURE/libpath
@@ -4480,7 +4467,7 @@ make install virtual
 			done
 		done
 		note * ...generated headers
-		loop HDR ast_release ast_standards ast_common ast_lib ast_sys lc align sig tmx tv ast_api ast_ccode ast_fcntl ast_float ast_fs ast_map ast_mmap ast_mode ast_ndbm ast_param ast_random ast_time ast_tty ast_limits ast_sizeof ast_dirent ast_iconv ast_nl_types ast_stdio ast_wchar ast_wctype
+		loop HDR ast_release ast_standards ast_common ast_lib ast_sys lc align sig tmx tv ast_api ast_ccode ast_fcntl ast_float ast_fs ast_map ast_mode ast_ndbm ast_param ast_random ast_time ast_tty ast_limits ast_sizeof ast_dirent ast_iconv ast_nl_types ast_stdio ast_wchar ast_wctype
 			make %{INCLUDE_AST}/%{HDR}.h
 				prev %{HDR}.h
 				exec - cp -f %{<} %{@}

src/lib/libast/include/ast.h

@@ -293,7 +293,6 @@ extern char*		astgetconf(const char*, const char*, const char*, int, Error_f);
 extern char*		astconf(const char*, const char*, const char*);
 extern Ast_confdisc_f	astconfdisc(Ast_confdisc_f);
 extern void		astconflist(Sfio_t*, const char*, int, const char*);
-extern off_t		astcopy(int, int, off_t);
 extern int		astquery(int, const char*, ...);
 extern void		astwinsize(int, int*, int*);
 #if _lib_sysconf

src/lib/libast/man/ast.3

@@ -48,7 +48,6 @@ long           astconf_long(\fIarg\fP);
 unsigned long  astconf_ulong(\fIarg\fP);
 Ast_confdisc_t astconfdisc(Ast_confdisc_t new_notify);
 void           astconflist(Sfio_t* stream, const char* path, int flags);
-off_t          astcopy(int \fIrfd\fP, int \fIwfd\fP, off_t \fIn\fP);
 int            astquery(int \fIfd\fP, const char* \fIformat\fP , ...);
 .EE
 .SH DESCRIPTION
@@ -223,29 +222,6 @@ snarfed for input to the
 .IR getconf (1)
 command.
 .PP
-.L astcopy
-efficiently copies up to
-.I n
-bytes from the file descriptor
-.I rfd
-to the file descriptor
-.IR wfd .
-The actual number of bytes copied is returned; \-1 is returned on error.
-If
-.I n
-is  0 then an optimal number of bytes (with respect to both
-.I rfd
-and
-.IR wfd )
-is copied.
-.PP
-If possible
-.IR mmap (2)
-is used to do the transfer.
-Some implementations may bypass user buffer copies usually required by the
-.IR read (2)- write (2)
-paradigm.
-.PP
 .L astquery
 outputs an
 .IR sfprintf (3)