Move OS::MemCopy and OS::MemMove out of platform to utils

src/regexp-stack.cc

Index: src/regexp-stack.cc
diff --git a/src/regexp-stack.cc b/src/regexp-stack.cc
index 5e250dd85ee706990a5a56b6a742f9d6a5ee5cbb..9122446d1d6bea153f493007f96b26437a6e88d2 100644
--- a/src/regexp-stack.cc
+++ b/src/regexp-stack.cc
@@ -33,7 +33,7 @@ RegExpStack::~RegExpStack() {
 
 char* RegExpStack::ArchiveStack(char* to) {
   size_t size = sizeof(thread_local_);
-  OS::MemCopy(reinterpret_cast<void*>(to), &thread_local_, size);
+  MemCopy(reinterpret_cast<void*>(to), &thread_local_, size);
   thread_local_ = ThreadLocal();
   return to + size;
 }
@@ -41,7 +41,7 @@ char* RegExpStack::ArchiveStack(char* to) {
 
 char* RegExpStack::RestoreStack(char* from) {
   size_t size = sizeof(thread_local_);
-  OS::MemCopy(&thread_local_, reinterpret_cast<void*>(from), size);
+  MemCopy(&thread_local_, reinterpret_cast<void*>(from), size);
   return from + size;
 }
 
@@ -69,11 +69,10 @@ Address RegExpStack::EnsureCapacity(size_t size) {
     Address new_memory = NewArray<byte>(static_cast<int>(size));
     if (thread_local_.memory_size_ > 0) {
       // Copy original memory into top of new memory.
-      OS::MemCopy(
-          reinterpret_cast<void*>(
-              new_memory + size - thread_local_.memory_size_),
-          reinterpret_cast<void*>(thread_local_.memory_),
-          thread_local_.memory_size_);
+      MemCopy(reinterpret_cast<void*>(new_memory + size -
+                                      thread_local_.memory_size_),
+              reinterpret_cast<void*>(thread_local_.memory_),
+              thread_local_.memory_size_);
       DeleteArray(thread_local_.memory_);
     }
     thread_local_.memory_ = new_memory;