patch 8.1.1531: clipboard type name is inconsistent

Problem:    Clipboard type name is inconsistent.
Solution:   Rename VimClipboard to Clipboard_T.
diff --git a/src/proto/ui.pro b/src/proto/ui.pro
index e920029..7b28a32 100644
--- a/src/proto/ui.pro
+++ b/src/proto/ui.pro
@@ -15,9 +15,9 @@
 void ui_breakcheck(void);
 void ui_breakcheck_force(int force);
 void clip_init(int can_use);
-void clip_update_selection(VimClipboard *clip);
-void clip_own_selection(VimClipboard *cbd);
-void clip_lose_selection(VimClipboard *cbd);
+void clip_update_selection(Clipboard_T *clip);
+void clip_own_selection(Clipboard_T *cbd);
+void clip_lose_selection(Clipboard_T *cbd);
 void start_global_changes(void);
 int is_clipboard_needs_update(void);
 void end_global_changes(void);
@@ -28,15 +28,15 @@
 void clip_start_selection(int col, int row, int repeated_click);
 void clip_process_selection(int button, int col, int row, int_u repeated_click);
 void clip_may_redraw_selection(int row, int col, int len);
-void clip_clear_selection(VimClipboard *cbd);
+void clip_clear_selection(Clipboard_T *cbd);
 void clip_may_clear_selection(int row1, int row2);
 void clip_scroll_selection(int rows);
 void clip_copy_modeless_selection(int both);
-int clip_gen_own_selection(VimClipboard *cbd);
-void clip_gen_lose_selection(VimClipboard *cbd);
-void clip_gen_set_selection(VimClipboard *cbd);
-void clip_gen_request_selection(VimClipboard *cbd);
-int clip_gen_owner_exists(VimClipboard *cbd);
+int clip_gen_own_selection(Clipboard_T *cbd);
+void clip_gen_lose_selection(Clipboard_T *cbd);
+void clip_gen_set_selection(Clipboard_T *cbd);
+void clip_gen_request_selection(Clipboard_T *cbd);
+int clip_gen_owner_exists(Clipboard_T *cbd);
 int vim_is_input_buf_full(void);
 int vim_is_input_buf_empty(void);
 int vim_free_in_input_buf(void);
@@ -57,12 +57,12 @@
 void open_app_context(void);
 void x11_setup_atoms(Display *dpy);
 void x11_setup_selection(Widget w);
-void clip_x11_request_selection(Widget myShell, Display *dpy, VimClipboard *cbd);
-void clip_x11_lose_selection(Widget myShell, VimClipboard *cbd);
-int clip_x11_own_selection(Widget myShell, VimClipboard *cbd);
-void clip_x11_set_selection(VimClipboard *cbd);
-int clip_x11_owner_exists(VimClipboard *cbd);
-void yank_cut_buffer0(Display *dpy, VimClipboard *cbd);
+void clip_x11_request_selection(Widget myShell, Display *dpy, Clipboard_T *cbd);
+void clip_x11_lose_selection(Widget myShell, Clipboard_T *cbd);
+int clip_x11_own_selection(Widget myShell, Clipboard_T *cbd);
+void clip_x11_set_selection(Clipboard_T *cbd);
+int clip_x11_owner_exists(Clipboard_T *cbd);
+void yank_cut_buffer0(Display *dpy, Clipboard_T *cbd);
 int jump_to_mouse(int flags, int *inclusive, int which_button);
 int mouse_comp_pos(win_T *win, int *rowp, int *colp, linenr_T *lnump);
 win_T *mouse_find_win(int *rowp, int *colp, mouse_find_T popup);