patch 9.0.1171: screen is not redrawn after using setcellwidths()

Problem:    Screen is not redrawn after using setcellwidths().
Solution:   Redraw the screen when the cell widths have changed. (Yasuhiro
            Matsumoto, closes #11800)

src/mbyte.c

@@ -5742,6 +5742,7 @@ f_setcellwidths(typval_T *argvars, typval_T *rettv UNUSED)
     }
 
     vim_free(cw_table_save);
+    redraw_all_later(UPD_CLEAR);
 }
 
     void

src/testdir/dumps/Test_setcellwidths_dump_1.dump

@@ -0,0 +1,6 @@
+>+0&#ffffff0|D|e|s|k|t|o|p| @66
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+| +0#0000000&@56|1|,|1| @10|A|l@1| 

src/testdir/dumps/Test_setcellwidths_dump_2.dump

@@ -0,0 +1,6 @@
+>+0&#ffffff0| |D|e|s|k|t|o|p| @65
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+| +0#0000000&@56|1|,|1| @10|A|l@1| 

src/testdir/test_utf8.vim

@@ -2,6 +2,7 @@
  
 source check.vim
 source view_util.vim
+source screendump.vim
 
 " Visual block Insert adjusts for multi-byte char
 func Test_visual_block_insert()
@@ -198,6 +199,22 @@ func Test_setcellwidths()
   call setcellwidths([])
 endfunc
 
+func Test_setcellwidths_dump()
+  CheckRunVimInTerminal
+
+  let lines =<< trim END
+      call setline(1, "\ue5ffDesktop")
+  END
+  call writefile(lines, 'XCellwidths', 'D')
+  let buf = RunVimInTerminal('-S XCellwidths', {'rows': 6})
+  call VerifyScreenDump(buf, 'Test_setcellwidths_dump_1', {})
+
+  call term_sendkeys(buf, ":call setcellwidths([[0xe5ff, 0xe5ff, 2]])\<CR>")
+  call VerifyScreenDump(buf, 'Test_setcellwidths_dump_2', {})
+
+  call StopVimInTerminal(buf)
+endfunc
+
 func Test_print_overlong()
   " Text with more composing characters than MB_MAXBYTES.
   new

src/version.c

@@ -695,6 +695,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1171,
 /**/
     1170,
 /**/