Initialize fast memmove methods in the Isolate's ctor

src/isolate.cc

 // Copyright 2012 the V8 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.
 
 #include "src/isolate.h"
 
 #include <stdlib.h>
 
 #include <fstream>  // NOLINT(readability/streams)
 #include <sstream>
@@ skipping 1818 matching lines @@
   ISOLATE_INIT_LIST(ISOLATE_INIT_EXECUTE)
 #undef ISOLATE_INIT_EXECUTE
 
 #define ISOLATE_INIT_ARRAY_EXECUTE(type, name, length)                         \
   memset(name##_, 0, sizeof(type) * length);
   ISOLATE_INIT_ARRAY_LIST(ISOLATE_INIT_ARRAY_EXECUTE)
 #undef ISOLATE_INIT_ARRAY_EXECUTE
 
   InitializeLoggingAndCounters();
   debug_ = new Debug(this);
+
+  init_memcopy_functions(this);
 }
 
 
 void Isolate::TearDown() {
   TRACE_ISOLATE(tear_down);
 
   // Temporarily set this isolate as current so that various parts of
   // the isolate can access it in their destructors without having a
   // direct pointer. We don't use Enter/Exit here to avoid
   // initializing the thread data.
@@ skipping 993 matching lines @@
   // Then check whether this scope intercepts.
   if ((flag & intercept_mask_)) {
     intercepted_flags_ |= flag;
     return true;
   }
   return false;
 }
 
 }  // namespace internal
 }  // namespace v8