Switching back to __builtin_bswap32.

ports/glibc-compat/include/machine/endian.h

 /*
  * Copyright 2014 The Native Client Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #ifndef GLIBCEMU_MACHINE_ENDIAN_H
 #define GLIBCEMU_MACHINE_ENDIAN_H 1
 
 #include_next <machine/endian.h>
 
 #include <_ansi.h>
 
 #define __byte_swap_constant_16(x) \
     ( (((unsigned short)(x) & 0xff) << 8) | \
        ((unsigned short)(x) >> 8) )
 
 #define __byte_swap_constant_32(x) \
     ( (((unsigned int)(x) & 0xff) << 24) | \
       (((unsigned int)(x) << 8) & 0x00ff0000) | \
       (((unsigned int)(x) >> 8) & 0x0000ff00) | \
        ((unsigned int)(x) >> 24) )
 
 
 _ELIDABLE_INLINE unsigned short int
 __inline_bswap_16 (unsigned short int x)
 {
     return __byte_swap_constant_16(x);
 }
 
-_ELIDABLE_INLINE unsigned long int
-__inline_bswap_32 (unsigned long int x)
-{
-    return __byte_swap_constant_32(x);
-}
-
 #define __byte_swap_16(x) \
   (__builtin_constant_p(x) ? __byte_swap_constant_16(x) : __inline_bswap_16(x))
 
 #define __byte_swap_32(x) \
-  (__builtin_constant_p(x) ? __byte_swap_constant_32(x) : __inline_bswap_32(x))
+  (__builtin_constant_p(x) ? __byte_swap_constant_32(x) : __builtin_bswap32(x))
 
 #define ntohs(x)   (unsigned int)__byte_swap_16(x)
 #define ntohl(x)   (unsigned int)__byte_swap_32(x)
 #define htons(x)   (unsigned int)__byte_swap_16(x)
 #define htonl(x)   (unsigned int)__byte_swap_32(x)
 
 #endif