Cast for clang-cl 64 bit build warnings in unittests

unit_test/cpu_test.cc

 /*
  *  Copyright 2012 The LibYuv Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE 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.
  */
 
@@ skipping 78 matching lines @@
     // NexGenDriven NexGen processor
     // RiseRiseRise Rise Technology processor
     // SiS SiS SiS  SiS processor
     // UMC UMC UMC  UMC processor
     CpuId(0, 0, cpu_info);
     cpu_info[0] = cpu_info[1];  // Reorder output
     cpu_info[1] = cpu_info[3];
     cpu_info[3] = 0;
     printf("Cpu Vendor: %s %x %x %x\n", reinterpret_cast<char*>(&cpu_info[0]),
            cpu_info[0], cpu_info[1], cpu_info[2]);
-    EXPECT_EQ(12, strlen(reinterpret_cast<char*>(&cpu_info[0])));
+    EXPECT_EQ(12u, strlen(reinterpret_cast<char*>(&cpu_info[0])));
 
     // CPU Family and Model
     // 3:0 - Stepping
     // 7:4 - Model
     // 11:8 - Family
     // 13:12 - Processor Type
     // 19:16 - Extended Model
     // 27:20 - Extended Family
     CpuId(1, 0, cpu_info);
     int family = ((cpu_info[0] >> 8) & 0x0f) | ((cpu_info[0] >> 16) & 0xff0);
@@ skipping 20 matching lines @@
     EXPECT_EQ(kCpuHasNEON, ArmCpuCaps("../../unit_test/testdata/juno.txt"));
   } else {
     printf("WARNING: unable to load \"../../unit_test/testdata/arm_v7.txt\"\n");
   }
 #if defined(__linux__) && defined(__ARM_NEON__)
   EXPECT_EQ(kCpuHasNEON, ArmCpuCaps("/proc/cpuinfo"));
 #endif
 }
 
 }  // namespace libyuv