sys/user.h: derive __WORDSIZE from __LONG_MAX

previously, only a few archs defined it here. this change makes the
presence consistent across all archs, and reduces the amount of header
duplication (and potential for future inconsistency) between archs.

arch/s390x/bits/user.h

@@ -1,6 +1,3 @@
-#undef __WORDSIZE
-#define __WORDSIZE 64
-
 typedef union {
 	double d;
 	float f;

arch/sh/bits/user.h

@@ -1,6 +1,3 @@
-#undef __WORDSIZE
-#define __WORDSIZE 32
-
 #define REG_REG0	 0
 #define REG_REG15	15
 #define REG_PC		16

arch/x32/bits/user.h

@@ -1,6 +1,3 @@
-#undef __WORDSIZE
-#define __WORDSIZE 32
-
 typedef struct user_fpregs_struct {
 	uint16_t cwd, swd, ftw, fop;
 	uint64_t rip, rdp;

arch/x86_64/bits/user.h

@@ -1,6 +1,3 @@
-#undef __WORDSIZE
-#define __WORDSIZE 64
-
 typedef struct user_fpregs_struct {
 	uint16_t cwd, swd, ftw, fop;
 	uint64_t rip, rdp;

include/sys/user.h

@@ -8,6 +8,15 @@ extern "C" {
 #include <stdint.h>
 #include <unistd.h>
 
+#include <bits/alltype.h>
+
+#undef __WORDSIZE
+#if __LONG_MAX == 0x7fffffffL
+#define __WORDSIZE 32
+#else
+#define __WORDSIZE 64
+#endif
+
 #include <bits/user.h>
 
 #ifdef __cplusplus