mesa: remove gl_framebuffer:_DepthBuffer, _StencilBuffer fields

These were used by swrast to make a combined depth+stencil buffer look
like separate depth and stencil buffers.  But that's no longer needed
after rewriting the depth/stencil code in swrast.

Reviewed-by: Eric Anholt <eric@anholt.net>

src/mesa/main/framebuffer.c

@@ -222,10 +222,6 @@ _mesa_free_framebuffer_data(struct gl_framebuffer *fb)
       ASSERT(!att->Texture);
       att->Type = GL_NONE;
    }
-
-   /* unbind _Depth/_StencilBuffer to decr ref counts */
-   _mesa_reference_renderbuffer(&fb->_DepthBuffer, NULL);
-   _mesa_reference_renderbuffer(&fb->_StencilBuffer, NULL);
 }
 
 
@@ -681,8 +677,6 @@ update_color_read_buffer(struct gl_context *ctx, struct gl_framebuffer *fb)
  *    _ColorDrawBuffers
  *    _NumColorDrawBuffers
  *    _ColorReadBuffer
- *    _DepthBuffer
- *    _StencilBuffer
  *
  * If the framebuffer is user-created, make sure it's complete.
  *

src/mesa/main/mtypes.h

@@ -2673,12 +2673,6 @@ struct gl_framebuffer
    struct gl_renderbuffer *_ColorDrawBuffers[MAX_DRAW_BUFFERS];
    struct gl_renderbuffer *_ColorReadBuffer;
 
-   /** Wrappers to make combined depth/stencil buffers look like separate
-    * buffers.  Only used by swrast.  Will be removed in the future.
-    */
-   struct gl_renderbuffer *_DepthBuffer;
-   struct gl_renderbuffer *_StencilBuffer;
-
    /** Delete this framebuffer */
    void (*Delete)(struct gl_framebuffer *fb);
 };