i965: Hack in avoidance of c++ reserved keyword in libdrm.

I'm also fixing this upstream in libdrm, but this avoids new libdrm
dependency for the moment.

src/mesa/drivers/dri/i965/brw_fs.cpp

@@ -26,6 +26,14 @@
  */
 
 extern "C" {
+
+#include <sys/types.h>
+/* Evil hack for using libdrm in a c++ compiler. */
+#define virtual virt
+#include "i915_drm.h"
+#include "intel_bufmgr.h"
+#undef virtual
+
 #include "main/macros.h"
 #include "main/shaderobj.h"
 #include "program/prog_parameter.h"