x86: Generate system call tables and unistd_*.h from tables

Generate system call tables and unistd_*.h automatically from the
tables in arch/x86/syscalls.  All other information, like NR_syscalls,
is auto-generated, some of which is in asm-offsets_*.c.

This allows us to keep all the system call information in one place,
and allows for kernel space and user space to see different
information; this is currently used for the ia32 system call numbers
when building the 64-bit kernel, but will be used by the x32 ABI in
the near future.

This also removes some gratuitious differences between i386, x86-64
and ia32; in particular, now all system call tables are generated with
the same mechanism.

Cc: H. J. Lu <hjl.tools@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

arch/x86/ia32/syscall_ia32.c

@@ -0,0 +1,25 @@
+/* System call table for ia32 emulation. */
+
+#include <linux/linkage.h>
+#include <linux/sys.h>
+#include <linux/cache.h>
+#include <asm/asm-offsets.h>
+
+#define __SYSCALL_I386(nr, sym, compat) extern asmlinkage void compat(void) ;
+#include <asm/syscalls_32.h>
+#undef __SYSCALL_I386
+
+#define __SYSCALL_I386(nr, sym, compat) [nr] = compat,
+
+typedef void (*sys_call_ptr_t)(void);
+
+extern void compat_ni_syscall(void);
+
+const sys_call_ptr_t ia32_sys_call_table[__NR_ia32_syscall_max+1] = {
+	/*
+	 * Smells like a like a compiler bug -- it doesn't work
+	 * when the & below is removed.
+	 */
+	[0 ... __NR_ia32_syscall_max] = &compat_ni_syscall,
+#include <asm/syscalls_32.h>
+};