added build env for VC++

src/ir_decoder/dllmain.c

@@ -0,0 +1,18 @@
+#include "stdafx.h"
+
+BOOL APIENTRY DllMain( HMODULE hModule,
+                       DWORD  ul_reason_for_call,
+                       LPVOID lpReserved
+					 )
+{
+	switch (ul_reason_for_call)
+	{
+	case DLL_PROCESS_ATTACH:
+	case DLL_THREAD_ATTACH:
+	case DLL_THREAD_DETACH:
+	case DLL_PROCESS_DETACH:
+		break;
+	}
+	return TRUE;
+}
+