Add x86_64 to the bionic headers.

Manual changes:

  cpp.py: cope with macros that refer to other macros.

  defaults.py: x86 no longer always implies __i386__; use __i386__ to replace
  the kernel CONFIG_X86_32 flag.

  asm/page.h: the upstream page.h isn't a uapi header and no longer includes
  the stuff we were using it for. Let's just have our own static file, since
  it's the same for all our architectures (both 32- and 64-bit).

  sys/select.h: we used to use the various FD_SET-related macros from the
  kernel header files, but they've gone. Adjust by adding trivial equivalent
  definitions.

Automated changes:

  libc/kernel/arch-x86, libc/kernel/common: regenerated from
  external/kernel-headers.

Change-Id: I84fc0ed52dc742e043b4ae300fd3b58ee99b7fcd
diff --git a/libc/kernel/arch-x86/asm/div64.h b/libc/kernel/arch-x86/asm/div64.h
index 420d9e3..4621ca7 100644
--- a/libc/kernel/arch-x86/asm/div64.h
+++ b/libc/kernel/arch-x86/asm/div64.h
@@ -18,8 +18,13 @@
  ****************************************************************************/
 #ifndef _ASM_X86_DIV64_H
 #define _ASM_X86_DIV64_H
+#ifdef __i386__
 #include <linux/types.h>
-#define do_div(n,base) ({   unsigned long __upper, __low, __high, __mod, __base;   __base = (base);   asm("":"=a" (__low), "=d" (__high):"A" (n));   __upper = __high;   if (__high) {   __upper = __high % (__base);   __high = __high / (__base);   }   asm("divl %2":"=a" (__low), "=d" (__mod):"rm" (__base), "0" (__low), "1" (__upper));   asm("":"=A" (n):"a" (__low),"d" (__high));   __mod;  })
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
+#define do_div(n,base) ({   unsigned long __upper, __low, __high, __mod, __base;   __base = (base);   asm("":"=a" (__low), "=d" (__high):"A" (n));   __upper = __high;   if (__high) {   __upper = __high % (__base);   __high = __high / (__base);   }   asm("divl %2":"=a" (__low), "=d" (__mod):"rm" (__base), "0" (__low), "1" (__upper));   asm("":"=A" (n):"a" (__low),"d" (__high));   __mod;  })
 #define div_long_long_rem(a,b,c) div_ll_X_l_rem(a,b,c)
+#else
+#include <asm-generic/div64.h>
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
+#endif
 #endif