OpenGL: remove fdrawline & other helper functions

Finally, fdrawline is no more!

Part of T49043 & T49450

source/blender/editors/include/BIF_glutil.h

@@ -38,7 +38,7 @@ struct bContext;
 struct ColorManagedViewSettings;
 struct ColorManagedDisplaySettings;
 
-/* Several functions defined here are being DEPRECATED for Blender 2.8
+/* A few functions defined here are being DEPRECATED for Blender 2.8
  *
  * Do not use them in new code, and you are encouraged to
  * convert existing code to draw without these.
@@ -47,8 +47,6 @@ struct ColorManagedDisplaySettings;
  * - merwin
  */
 
-void fdrawline(float x1, float y1, float x2, float y2); /* DEPRECATED */
-
 /**
  * Draw a circle outline with the given \a radius.
  * The circle is centered at \a x, \a y and drawn in the XY plane.

source/blender/editors/interface/interface_panel.c

@@ -50,9 +50,6 @@
 #include "BKE_context.h"
 #include "BKE_screen.h"
 
-#include "BIF_gl.h"
-#include "BIF_glutil.h"
-
 #include "BLF_api.h"
 
 #include "WM_api.h"
@@ -395,22 +392,6 @@ static void ui_offset_panel_block(uiBlock *block)
 
 /**************************** drawing *******************************/
 
-/* extern used by previewrender */
-#if 0 /*UNUSED 2.5*/
-static void uiPanelPush(uiBlock *block)
-{
-	glPushMatrix(); 
-
-	if (block->panel)
-		glTranslatef((float)block->panel->ofsx, (float)block->panel->ofsy, 0.0);
-}
-
-static void uiPanelPop(uiBlock *UNUSED(block))
-{
-	glPopMatrix();
-}
-#endif
-
 /* triangle 'icon' for panel header */
 void UI_draw_icon_tri(float x, float y, char dir, const float color[4])
 {

source/blender/editors/screen/glutil.c

@@ -54,15 +54,6 @@
 
 #include "UI_interface.h"
 
-/* DEPRECATED: use imm_draw_line instead */
-void fdrawline(float x1, float y1, float x2, float y2)
-{
-	glBegin(GL_LINES);
-	glVertex2f(x1, y1);
-	glVertex2f(x2, y2);
-	glEnd();
-}
-
 /* ******************************************** */
 
 void setlinestyle(int nr)