Make nsgmls compile on OpenBSD.

As far as I can tell, the duplicate instantiations from entmgr_inst.m4 are
unnecessary and only cause compile failures without -fpermissive.

cde/programs/nsgmls/OutputCharStream.C

@@ -28,7 +28,7 @@
 #include "OutputCharStream.h"
 #include "CodingSystem.h"
 #include "macros.h"
-#if defined(linux)
+#if defined(linux) || defined(CSRG_BASED)
 #include <iostream>
 #else
 #include <iostream.h>
@@ -148,7 +148,7 @@ void IosOutputCharStream::flush()
     encoder_->output(buf_, ptr_ - buf_, byteStream_);
     ptr_ = buf_;
   }
-#if defined(linux)
+#if defined(linux) || defined(CSRG_BASED)
   byteStream_->pubsync();
 #else
   byteStream_->sync();