patch 9.1.0433: Wrong yanking with exclusive selection and ve=all

Problem:  Wrong yanking with exclusive selection and virtualedit=all,
          and integer overflow when using getregion() on it.
Solution: Set coladd when decreasing column and 'virtualedit' is active.
          Add more tests for getregion() with 'virtualedit' (zeertzjq).

closes: #14830

Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/proto/normal.pro b/src/proto/normal.pro
index 6dcbe41..36a26ec 100644
--- a/src/proto/normal.pro
+++ b/src/proto/normal.pro
@@ -31,5 +31,6 @@
 void start_selection(void);
 void may_start_select(int c);
 int unadjust_for_sel(void);
+int unadjust_for_sel_inner(pos_T *pp);
 void set_cursor_for_append_to_line(void);
 /* vim: set ft=c : */