A64: Synchronize with r17441.

src/a64/cpu-a64.h

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 50 matching lines @@
     return (IsSupported(f) &&
             (!Serializer::enabled() || !IsFoundByRuntimeProbingOnly(f)));
   }
 
   // I and D cache line size in bytes.
   static unsigned dcache_line_size();
   static unsigned icache_line_size();
 
   static unsigned supported_;
 
+  static bool VerifyCrossCompiling() {
+    // There are no optional features for A64.
+    ASSERT(cross_compile_ == 0);
+    return true;
+  }
+
+  static bool VerifyCrossCompiling(CpuFeature f) {
+    // There are no optional features for A64.
+    USE(f);
+    ASSERT(cross_compile_ == 0);
+    return true;
+  }
+
  private:
   // Return the content of the cache type register.
   static uint32_t GetCacheType();
 
   // I and D cache line size in bytes.
   static unsigned icache_line_size_;
   static unsigned dcache_line_size_;
 
 #ifdef DEBUG
   static bool initialized_;
 #endif
 
   // This isn't used (and is always 0), but it is required by V8.
   static unsigned found_by_runtime_probing_only_;
 
+  static unsigned cross_compile_;
+
   friend class PlatformFeatureScope;
   DISALLOW_COPY_AND_ASSIGN(CpuFeatures);
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_A64_CPU_A64_H_