Revert 21502 - "Move OS::MemCopy and OS::MemMove out of platform to utils"

src/isolate.cc

Index: src/isolate.cc
diff --git a/src/isolate.cc b/src/isolate.cc
index 3a8bfa637c4c29edb1503c07a7576954019445d9..d204726f8b0a8d2c19be2b36c08ace15c53a9864 100644
--- a/src/isolate.cc
+++ b/src/isolate.cc
@@ -1343,8 +1343,8 @@ Handle<Context> Isolate::GetCallingNativeContext() {
 
 
 char* Isolate::ArchiveThread(char* to) {
-  MemCopy(to, reinterpret_cast<char*>(thread_local_top()),
-          sizeof(ThreadLocalTop));
+  OS::MemCopy(to, reinterpret_cast<char*>(thread_local_top()),
+              sizeof(ThreadLocalTop));
   InitializeThreadLocal();
   clear_pending_exception();
   clear_pending_message();
@@ -1354,10 +1354,10 @@ char* Isolate::ArchiveThread(char* to) {
 
 
 char* Isolate::RestoreThread(char* from) {
-  MemCopy(reinterpret_cast<char*>(thread_local_top()), from,
-          sizeof(ThreadLocalTop));
-// This might be just paranoia, but it seems to be needed in case a
-// thread_local_top_ is restored on a separate OS thread.
+  OS::MemCopy(reinterpret_cast<char*>(thread_local_top()), from,
+              sizeof(ThreadLocalTop));
+  // This might be just paranoia, but it seems to be needed in case a
+  // thread_local_top_ is restored on a separate OS thread.
 #ifdef USE_SIMULATOR
   thread_local_top()->simulator_ = Simulator::current(this);
 #endif