Cherry pick MIPS build fix

source/libvpx/vpx_util/endian_inl.h

 // Copyright 2014 Google Inc. All Rights Reserved.
 //
 // Use of this source code is governed by a BSD-style license
 // that can be found in the COPYING file in the root of the source
 // 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.
 // -----------------------------------------------------------------------------
 //
 // Endian related functions.
@@ skipping 45 matching lines @@
 // clang-3.3 and gcc-4.3 have builtin functions for swap32/swap64
 #if LOCAL_GCC_PREREQ(4, 3) || LOCAL_CLANG_PREREQ(3, 3)
 #define HAVE_BUILTIN_BSWAP32
 #define HAVE_BUILTIN_BSWAP64
 #endif
 // clang-3.3 and gcc-4.8 have a builtin function for swap16
 #if LOCAL_GCC_PREREQ(4, 8) || LOCAL_CLANG_PREREQ(3, 3)
 #define HAVE_BUILTIN_BSWAP16
 #endif
 
+#if HAVE_MIPS32 && defined(__mips__) && !defined(__mips64) && \
+    defined(__mips_isa_rev) && (__mips_isa_rev >= 2) && (__mips_isa_rev < 6)
+#define VPX_USE_MIPS32_R2
+#endif
+
 static INLINE uint16_t BSwap16(uint16_t x) {
 #if defined(HAVE_BUILTIN_BSWAP16)
   return __builtin_bswap16(x);
 #elif defined(_MSC_VER)
   return _byteswap_ushort(x);
 #else
   // gcc will recognize a 'rorw $8, ...' here:
   return (x >> 8) | ((x & 0xff) << 8);
 #endif  // HAVE_BUILTIN_BSWAP16
 }
 
 static INLINE uint32_t BSwap32(uint32_t x) {
-#if HAVE_MIPS32
+#if defined(VPX_USE_MIPS32_R2)
   uint32_t ret;
   __asm__ volatile (
     "wsbh   %[ret], %[x]          \n\t"
     "rotr   %[ret], %[ret],  16   \n\t"
     : [ret]"=r"(ret)
     : [x]"r"(x)
   );
   return ret;
 #elif defined(HAVE_BUILTIN_BSWAP32)
   return __builtin_bswap32(x);
@@ skipping 19 matching lines @@
   return (uint64_t)_byteswap_uint64(x);
 #else  // generic code for swapping 64-bit values (suggested by bdb@)
   x = ((x & 0xffffffff00000000ull) >> 32) | ((x & 0x00000000ffffffffull) << 32);
   x = ((x & 0xffff0000ffff0000ull) >> 16) | ((x & 0x0000ffff0000ffffull) << 16);
   x = ((x & 0xff00ff00ff00ff00ull) >>  8) | ((x & 0x00ff00ff00ff00ffull) <<  8);
   return x;
 #endif  // HAVE_BUILTIN_BSWAP64
 }
 
 #endif  // VPX_UTIL_ENDIAN_INL_H_