Merge https://github.com/coelckers/gzdoom

# Conflicts:
#	src/r_bsp.cpp
#	src/r_main.cpp
#	src/r_segs.cpp
#	src/r_things.cpp
#	wadsrc/static/language.enu
#	wadsrc/static/menudef.txt

src/v_draw.cpp

@@ -1318,7 +1318,7 @@ void DCanvas::FinishSimplePolys()
 
 void DCanvas::FillSimplePoly(FTexture *tex, FVector2 *points, int npoints,
 	double originx, double originy, double scalex, double scaley, DAngle rotation,
-	FDynamicColormap *colormap, int lightlevel, int bottomclip)
+	FDynamicColormap *colormap, PalEntry flatcolor, int lightlevel, int bottomclip)
 {
 #ifndef NO_SWRENDER
         using namespace swrenderer;