Fixes build. https://bugs.gentoo.org/706930#c8

--- freedroidrpg-1.0RC2/src/global.h	2019-03-30 23:20:31.000000000 +1000
+++ freedroidrpg-1.0RC2/src/global.h	2020-06-21 20:51:01.566218463 +1000
@@ -36,7 +36,6 @@ 
 #define INTERN_FOR _main_c
 #include "extint_macros.h"
 
-EXTERN float FPSover1;
 EXTERN char *AllSkillTexts[];
 EXTERN char font_switchto_red[];
 EXTERN char font_switchto_blue[];
--- freedroidrpg-1.0RC2/src/lvledit/lvledit_tools.h	2019-03-30 23:20:31.000000000 +1000
+++ freedroidrpg-1.0RC2/src/lvledit/lvledit_tools.h	2020-06-21 20:41:58.424710693 +1000
@@ -36,7 +36,7 @@ 
 
 void leveleditor_init_tools(void);
 
-struct leveleditor_tool tool_place, tool_move, tool_select;
+EXTERN struct leveleditor_tool tool_place, tool_move, tool_select;
 
 #define EVENT_LEFT_PRESS(e) (((e) && e->type == SDL_MOUSEBUTTONDOWN) && (e->button.button == 1))
 #define EVENT_RIGHT_PRESS(e) (((e) && e->type == SDL_MOUSEBUTTONDOWN) && (e->button.button == 3))
--- freedroidrpg-1.0RC2/src/mapgen/mapgen.h	2019-03-30 23:20:31.000000000 +1000
+++ freedroidrpg-1.0RC2/src/mapgen/mapgen.h	2020-06-21 20:43:53.255723534 +1000
@@ -64,9 +64,9 @@ 
 extern int total_rooms;
 
 // Interface to the game
-void (*dungeonmap_convert) (int, int, unsigned char *);
-void (*dungeonmap_place_enemies) (struct roominfo *);
-void (*dungeonmap_gift) (struct roominfo *);
+extern void (*dungeonmap_convert) (int, int, unsigned char *);
+extern void (*dungeonmap_place_enemies) (struct roominfo *);
+extern void (*dungeonmap_gift) (struct roominfo *);
 
 int generate_dungeon_gram(int, int);
 
--- freedroidrpg-1.0RC2/src/struct.h	2019-05-13 01:03:36.000000000 +1000
+++ freedroidrpg-1.0RC2/src/struct.h	2020-06-21 20:38:22.189812908 +1000
@@ -1063,7 +1063,7 @@ 
 	struct tux_part_instances default_instances;    // Default part instances
 	tux_part_render_motionclass *render_order;      // The render_sets of each motion class
 	int gun_muzzle_height;							// Vertical offset to apply to bullets
-} tux_rendering;
+};
 
 /**
  * Contains a set of Tux's parts images for a motion class.