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/sram_alloc.c b/sram_alloc.c
index b524c7b..a27941a 100644
--- a/sram_alloc.c
+++ b/sram_alloc.c
@@ -6,8 +6,7 @@
 
 #include "xlat/sram_alloc_flags.h"
 
-int
-sys_sram_alloc(struct tcb *tcp)
+SYS_FUNC(sram_alloc)
 {
 	if (entering(tcp)) {
 		/* size */