include: Always use _setjmpex on non-i386 platforms.

include/msvcrt/setjmp.h

@@ -147,30 +147,36 @@ extern "C" {
 
 _ACRTIMP void __cdecl longjmp(jmp_buf,int);
 
-#ifdef _WIN64
+#ifndef __has_builtin
-# ifdef _UCRT
+# define __has_builtin(x) 0
+#endif
+
+#ifdef _UCRT
+# ifdef __i386__
+#  define _setjmp __intrinsic_setjmp
+# else
 #  define _setjmpex __intrinsic_setjmpex
 # endif
-# if defined(__GNUC__) || defined(__clang__)
-_ACRTIMP int __cdecl __attribute__ ((__nothrow__,__returns_twice__)) _setjmpex(jmp_buf,void*);
-# define setjmp(buf)   _setjmpex(buf,__builtin_frame_address(0))
-# define setjmpex(buf) _setjmpex(buf,__builtin_frame_address(0))
-# endif
-#else  /* _WIN64 */
-# ifdef _UCRT
-#  define _setjmp __intrinsic_setjmp
-# endif
-# if defined(__GNUC__) || defined(__clang__)
-_ACRTIMP int __cdecl __attribute__ ((__nothrow__,__returns_twice__)) _setjmp(jmp_buf);
-# else
-_ACRTIMP int __cdecl _setjmp(jmp_buf);
-# endif
-#endif  /* _WIN64 */
-
-#ifndef setjmp
-#define setjmp _setjmp
 #endif
 
+#ifdef __i386__
+# if defined(_setjmp) || !__has_builtin(_setjmp)
+_ACRTIMP int __cdecl __attribute__((__nothrow__,__returns_twice__)) _setjmp(jmp_buf);
+# endif
+# define setjmp(buf) _setjmp((buf))
+#else  /* __i386__ */
+# if defined(_setjmpex) || !__has_builtin(_setjmpex)
+_ACRTIMP int __cdecl __attribute__((__nothrow__,__returns_twice__)) _setjmpex(jmp_buf,void*);
+# endif
+# if __has_builtin(__builtin_sponentry)
+#  define setjmp(buf) _setjmpex((buf), __builtin_sponentry())
+# elif __has_builtin(__builtin_frame_address)
+#  define setjmp(buf) _setjmpex((buf), __builtin_frame_address(0))
+# else
+#  define setjmp(buf) _setjmpex((buf), NULL)
+# endif
+#endif  /* __i386__ */
+
 #ifdef __cplusplus
 }
 #endif