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/ioprio.c b/ioprio.c
index 6826e56..20866dc 100644
--- a/ioprio.c
+++ b/ioprio.c
@@ -42,8 +42,7 @@
 	return outstr;
 }
 
-int
-sys_ioprio_get(struct tcb *tcp)
+SYS_FUNC(ioprio_get)
 {
 	if (entering(tcp)) {
 		/* int which */
@@ -60,8 +59,7 @@
 	}
 }
 
-int
-sys_ioprio_set(struct tcb *tcp)
+SYS_FUNC(ioprio_set)
 {
 	if (entering(tcp)) {
 		/* int which */