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

src/x87/assembler-x87.cc

Index: src/x87/assembler-x87.cc
diff --git a/src/x87/assembler-x87.cc b/src/x87/assembler-x87.cc
index 0d2c0a3821c5db2d0f421a7ba64ec2274e1eaa87..d40e8c5356d7db60ed29382c9b084cb0704d7c1d 100644
--- a/src/x87/assembler-x87.cc
+++ b/src/x87/assembler-x87.cc
@@ -1876,9 +1876,9 @@ void Assembler::GrowBuffer() {
   // Copy the data.
   int pc_delta = desc.buffer - buffer_;
   int rc_delta = (desc.buffer + desc.buffer_size) - (buffer_ + buffer_size_);
-  OS::MemMove(desc.buffer, buffer_, desc.instr_size);
-  OS::MemMove(rc_delta + reloc_info_writer.pos(),
-              reloc_info_writer.pos(), desc.reloc_size);
+  MemMove(desc.buffer, buffer_, desc.instr_size);
+  MemMove(rc_delta + reloc_info_writer.pos(), reloc_info_writer.pos(),
+          desc.reloc_size);
 
   // Switch buffers.
   if (isolate()->assembler_spare_buffer() == NULL &&