Fix various header freestanding issues

common/include/internal.h

@@ -6,10 +6,10 @@
  */
 /* prototypes for function calls between files within the OpenGL module */
 
-#ifndef _INTERNAL_H_
-#define _INTERNAL_H_
+#pragma once
 
 #include "ogl_init.h" // interface to OpenGL module
+#include "gr.h"
 
 #ifdef __cplusplus
 
@@ -68,5 +68,3 @@ extern void ogl_swap_buffers_internal(void);
 //inline GLfloat PAL2Tb(int c);
 
 #endif
-
-#endif // _INTERNAL_H_

common/include/valptridx.h

@@ -9,6 +9,7 @@
 #include <stdexcept>
 #include <string>
 #include "fwdvalptridx.h"
+#include "compiler-array.h"
 #include "compiler-static_assert.h"
 #include "compiler-type_traits.h"
 #include "pack.h"

common/main/automap.h

@@ -40,7 +40,7 @@ extern void automap_clear_visited();
 extern array<ubyte, MAX_SEGMENTS> Automap_visited;
 
 #if defined(DXX_BUILD_DESCENT_II)
-#include "objnum.h"
+#include "fwdobject.h"
 #include "ntstring.h"
 #include "window.h"