From: Jory A. Pratt <anarchy@gentoo.org>

sys/auvx.h avaliable on more then just glibc systems

diff --git a/media/webrtc/trunk/webrtc/system_wrappers/source/cpu_features_linux.c b/media/webrtc/trunk/webrtc/system_wrappers/source/cpu_features_linux.c
--- a/media/webrtc/trunk/webrtc/system_wrappers/source/cpu_features_linux.c
+++ b/media/webrtc/trunk/webrtc/system_wrappers/source/cpu_features_linux.c
@@ -6,20 +6,17 @@
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #include <stdlib.h>
 #include <string.h>
 #include <features.h>
-#ifndef __GLIBC_PREREQ
-#define __GLIBC_PREREQ(a, b) 0
-#endif
-#if __GLIBC_PREREQ(2, 16)
+#if defined(__linux__)
 #include <sys/auxv.h>
 #else
 #include <fcntl.h>
 #include <unistd.h>
 #include <errno.h>
 #include <link.h>
 #endif
 #include "system_wrappers/include/cpu_features_wrapper.h"
@@ -27,17 +24,17 @@
 #if defined(WEBRTC_ARCH_ARM_FAMILY)
 #include <asm/hwcap.h>
 
 uint64_t WebRtc_GetCPUFeaturesARM(void) {
   uint64_t result = 0;
   int architecture = 0;
   unsigned long hwcap = 0;
   const char* platform = NULL;
-#if __GLIBC_PREREQ(2, 16)
+#if defined(__linux__)
   hwcap = getauxval(AT_HWCAP);
   platform = (const char*)getauxval(AT_PLATFORM);
 #else
   ElfW(auxv_t) auxv;
   int fd = open("/proc/self/auxv", O_RDONLY);
   if (fd >= 0) {
     while (hwcap == 0 || platform == NULL) {
       if (read(fd, &auxv, sizeof(auxv)) < (ssize_t)sizeof(auxv)) {
@@ -51,17 +48,17 @@ uint64_t WebRtc_GetCPUFeaturesARM(void) 
           break;
         case AT_PLATFORM:
           platform = (const char*)auxv.a_un.a_val;
           break;
       }
     }
     close(fd);
   }
-#endif  // __GLIBC_PREREQ(2,16)
+#endif  // (__linux__)
 #if defined(__aarch64__)
   architecture = 8;
   if ((hwcap & HWCAP_FP) != 0)
     result |= kCPUFeatureVFPv3;
   if ((hwcap & HWCAP_ASIMD) != 0)
     result |= kCPUFeatureNEON;
 #else
   if (platform != NULL) {