Add include files so that IceCompilerServer.cpp can compile on MSC.

src/IceCompileServer.cpp

 //===- subzero/src/IceCompileServer.cpp - Compile server ------------------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 15 matching lines @@
 #include "llvm/Support/raw_os_ostream.h"
 #include "llvm/Support/Signals.h"
 #include "llvm/Support/SourceMgr.h"
 #include "llvm/Support/StreamingMemoryObject.h"
 #pragma clang diagnostic pop
 
 #include <fstream>
 #include <iostream>
 #include <thread>
 
+#if defined(HAVE_UNISTD_H)
+# include <unistd.h>
+#endif
+#if defined(_MSC_VER)
+# include <io.h>
+# include <fcntl.h>
+#endif
+
 namespace Ice {
 
 namespace {
 
 // Define a SmallVector backed buffer as a data stream, so that it can hold the
 // generated binary version of the textual bitcode in the input file.
 class TextDataStreamer : public llvm::DataStreamer {
 public:
   TextDataStreamer() = default;
   ~TextDataStreamer() final = default;
@@ skipping 154 matching lines @@
     });
     CompileThread.join();
   } else {
     getCompiler().run(ExtraFlags, *Ctx.get(), std::move(InputStream));
   }
   transferErrorCode(getReturnValue(
       ExtraFlags, static_cast<ErrorCodes>(Ctx->getErrorStatus()->value())));
 }
 
 } // end of namespace Ice