gallium: added cso_delete_vertex_fragment_shader() functions

The state tracker now uses these functions to free shaders, rather than
the pipe->delete_vs/fs-state() functions.  Before, we could get in a situation
where we free() a shader and happen to alloc() a new one at the same address.
The cso_set_vertex/fragment_shader() function would no-op the state change
since the pointers were the same.  This led to problems elsewhere, of course.

The new delete functions null-out the CSO's current shader pointers.

src/gallium/auxiliary/cso_cache/cso_context.c

@@ -471,6 +471,8 @@ void cso_restore_rasterizer(struct cso_context *ctx)
    ctx->rasterizer_saved = NULL;
 }
 
+
+
 enum pipe_error cso_set_fragment_shader_handle(struct cso_context *ctx,
                                                void *handle )
 {
@@ -481,6 +483,13 @@ enum pipe_error cso_set_fragment_shader_handle(struct cso_context *ctx,
    return PIPE_OK;
 }
 
+void cso_delete_fragment_shader(struct cso_context *ctx, void *handle )
+{
+   if (handle == ctx->fragment_shader)
+      ctx->pipe->bind_fs_state(ctx->pipe, NULL);
+   ctx->pipe->delete_fs_state(ctx->pipe, handle);
+   ctx->fragment_shader = NULL;
+}
 
 /* Not really working:
  */
@@ -553,6 +562,14 @@ enum pipe_error cso_set_vertex_shader_handle(struct cso_context *ctx,
    return PIPE_OK;
 }
 
+void cso_delete_vertex_shader(struct cso_context *ctx, void *handle )
+{
+   if (handle == ctx->vertex_shader)
+      ctx->pipe->bind_vs_state(ctx->pipe, NULL);
+   ctx->pipe->delete_vs_state(ctx->pipe, handle);
+   ctx->vertex_shader = NULL;
+}
+
 
 /* Not really working:
  */

src/gallium/auxiliary/cso_cache/cso_context.h

@@ -99,16 +99,22 @@ void cso_restore_sampler_textures( struct cso_context *cso );
  */
 enum pipe_error cso_set_fragment_shader_handle(struct cso_context *ctx,
                                                void *handle );
+void cso_delete_fragment_shader(struct cso_context *ctx, void *handle );
+/*
 enum pipe_error cso_set_fragment_shader( struct cso_context *cso,
                                          const struct pipe_shader_state *shader );
+*/
 void cso_save_fragment_shader(struct cso_context *cso);
 void cso_restore_fragment_shader(struct cso_context *cso);
 
 
 enum pipe_error cso_set_vertex_shader_handle(struct cso_context *ctx,
                                              void *handle );
+void cso_delete_vertex_shader(struct cso_context *ctx, void *handle );
+/*
 enum pipe_error cso_set_vertex_shader( struct cso_context *cso,
                                        const struct pipe_shader_state *shader );
+*/
 void cso_save_vertex_shader(struct cso_context *cso);
 void cso_restore_vertex_shader(struct cso_context *cso);