patch 9.0.0092: plugins cannot change v:completed_item

Problem:    Plugins cannot change v:completed_item.
Solution:   Make v:completed_item writeable. (Shougo Matsushita,
            closes #10801)
diff --git a/src/evalvars.c b/src/evalvars.c
index 7e6bf7a..16dfd0d 100644
--- a/src/evalvars.c
+++ b/src/evalvars.c
@@ -111,7 +111,7 @@
     {VV_NAME("oldfiles",	 VAR_LIST), &t_list_string, 0},
     {VV_NAME("windowid",	 VAR_NUMBER), NULL, VV_RO},
     {VV_NAME("progpath",	 VAR_STRING), NULL, VV_RO},
-    {VV_NAME("completed_item",	 VAR_DICT), &t_dict_string, VV_RO},
+    {VV_NAME("completed_item",	 VAR_DICT), &t_dict_string, 0},
     {VV_NAME("option_new",	 VAR_STRING), NULL, VV_RO},
     {VV_NAME("option_old",	 VAR_STRING), NULL, VV_RO},
     {VV_NAME("option_oldlocal",	 VAR_STRING), NULL, VV_RO},
diff --git a/src/testdir/test_ins_complete.vim b/src/testdir/test_ins_complete.vim
index 7bebc5d..35c5785 100644
--- a/src/testdir/test_ins_complete.vim
+++ b/src/testdir/test_ins_complete.vim
@@ -387,6 +387,19 @@
   au! CompleteDone
 endfunc
 
+func Test_CompleteDone_modify()
+  let value = {
+        \ 'word': '',
+        \ 'abbr': '',
+        \ 'menu': '',
+        \ 'info': '',
+        \ 'kind': '',
+        \ 'user_data': '',
+        \ }
+  let v:completed_item = value
+  call assert_equal(v:completed_item, value)
+endfunc
+
 func CompleteTest(findstart, query)
   if a:findstart
     return col('.')
diff --git a/src/version.c b/src/version.c
index 5adb215..4d97dcd 100644
--- a/src/version.c
+++ b/src/version.c
@@ -736,6 +736,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    92,
+/**/
     91,
 /**/
     90,