x86, um: Use the same style generated syscall tables as native

Now when the native kernel uses a single style of generated system
call table, follow suite for UML and implement the same style, all in
C.  This requires __NR_syscall_max and NR_syscalls to be generated; on
native this is done in asm-headers.h but that file is common to all
UML architectures; therefore put it in user-headers.h instead which
already have accommodations for architecture-specific values.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/arch/x86/um/user-offsets.c b/arch/x86/um/user-offsets.c
index ca49be8..5edf4f4 100644
--- a/arch/x86/um/user-offsets.c
+++ b/arch/x86/um/user-offsets.c
@@ -8,6 +8,18 @@
 #include <asm/ptrace.h>
 #include <asm/types.h>
 
+#ifdef __i386__
+#define __SYSCALL_I386(nr, sym, compat) [nr] = 1,
+static char syscalls[] = {
+#include <asm/syscalls_32.h>
+};
+#else
+#define __SYSCALL_64(nr, sym, compat) [nr] = 1,
+static char syscalls[] = {
+#include <asm/syscalls_64.h>
+};
+#endif
+
 #define DEFINE(sym, val) \
 	asm volatile("\n->" #sym " %0 " #val : : "i" (val))
 
@@ -77,4 +89,7 @@
 	DEFINE(UM_PROT_READ, PROT_READ);
 	DEFINE(UM_PROT_WRITE, PROT_WRITE);
 	DEFINE(UM_PROT_EXEC, PROT_EXEC);
+
+	DEFINE(__NR_syscall_max, sizeof(syscalls) - 1);
+	DEFINE(NR_syscalls, sizeof(syscalls));
 }