Avoid weak-linked getauxval support on non-linux platforms (like macOS)

configure.ac

@@ -1116,8 +1116,10 @@ AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
 
 AC_MSG_CHECKING(for weak getauxval support in the compiler)
 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+    #ifdef __linux__
     unsigned long getauxval(unsigned long type) __attribute__((weak));
     #define AT_HWCAP 16
+    #endif
   ]], [[
     getauxval(AT_HWCAP);
   ]])],