Declare syscall parsers using SYS_FUNC macro

Introduce SYS_FUNC macro to declare and define all syscall parsers.

* Makefile.am (BUILT_SOURCES, CLEANFILES): Add sys_func.h.
(sys_func.h): New rule.
* defs.h (SYS_FUNC_NAME, SYS_FUNC): New macros.
* linux/syscall.h: Include "sys_func.h".
[NEED_UID16_PARSERS]: Use SYS_FUNC to declare uid16 syscall parsers.
Remove other declarations.
* linux/alpha/syscallent.h (160, 161): Add sys_ prefix to osf_statfs
and osf_fstatfs syscall parsers.
* *.c: Use SYS_FUNC to define syscall parsers.
diff --git a/access.c b/access.c
index f28f69d..dd0d749 100644
--- a/access.c
+++ b/access.c
@@ -15,14 +15,12 @@
 	return 0;
 }
 
-int
-sys_access(struct tcb *tcp)
+SYS_FUNC(access)
 {
 	return decode_access(tcp, 0);
 }
 
-int
-sys_faccessat(struct tcb *tcp)
+SYS_FUNC(faccessat)
 {
 	if (entering(tcp))
 		print_dirfd(tcp, tcp->u_arg[0]);