[netbsd] d: Fix build failures on sparc*-netbsd

gcc/ChangeLog:

2019-04-27  Iain Buclaw  <ibuclaw@gdcproject.org>

	* config/netbsd-d.c: Include memmodel.h.  Remove unused tree.h,
	varasm.h, and netbsd-protos.h.

From-SVN: r270625

gcc/ChangeLog

+2019-04-27  Iain Buclaw  <ibuclaw@gdcproject.org>
+
+	* config/netbsd-d.c: Include memmodel.h.  Remove unused tree.h,
+	varasm.h, and netbsd-protos.h.
+
 2019-04-27  Uroš Bizjak  <ubizjak@gmail.com>
 
 	PR target/89261

gcc/config/netbsd-d.c

@@ -21,9 +21,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "system.h"
 #include "coretypes.h"
 #include "tm.h"
-#include "tree.h"
-#include "varasm.h"
-#include "netbsd-protos.h"
+#include "memmodel.h"
 #include "tm_p.h"
 #include "d/d-target.h"
 #include "d/d-target-def.h"