libwebp: update to 0.4.2-rc2

third_party/libwebp/dsp/cpu.c

 // Copyright 2011 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.
 // -----------------------------------------------------------------------------
 //
 // CPU detection
@@ skipping 39 matching lines @@
   const uint32_t ecx = 0;
   uint32_t eax, edx;
   // Use the raw opcode for xgetbv for compatibility with older toolchains.
   __asm__ volatile (
     ".byte 0x0f, 0x01, 0xd0\n"
     : "=a"(eax), "=d"(edx) : "c" (ecx));
   return ((uint64_t)edx << 32) | eax;
 }
 #elif defined(_MSC_FULL_VER) && _MSC_FULL_VER >= 160040219  // >= VS2010 SP1
 #define xgetbv() _xgetbv(0)
-#elif defined(_M_IX86)
+#elif defined(_MSC_VER) && defined(_M_IX86)
 static WEBP_INLINE uint64_t xgetbv(void) {
   uint32_t eax_, edx_;
   __asm {
     xor ecx, ecx  // ecx = 0
     // Use the raw opcode for xgetbv for compatibility with older toolchains.
     __asm _emit 0x0f __asm _emit 0x01 __asm _emit 0xd0
     mov eax_, eax
     mov edx_, edx
   }
   return ((uint64_t)edx_ << 32) | eax_;
@@ skipping 50 matching lines @@
 #elif defined(WEBP_USE_MIPS32)
 static int mipsCPUInfo(CPUFeature feature) {
   (void)feature;
   return 1;
 }
 VP8CPUInfo VP8GetCPUInfo = mipsCPUInfo;
 #else
 VP8CPUInfo VP8GetCPUInfo = NULL;
 #endif