patch 8.2.4149: test override not restored, autocommand left behind

Problem:    Test override not restored, autocommand left behind.
Solution:   Correct restoring test override.  Delete autocommand afterwards.

src/testdir/test_autocmd.vim

@@ -2038,7 +2038,7 @@ func Test_TextChangedI_with_setline()
   call assert_equal('', getline(1))
   call assert_equal('', getline(2))
 
-  call test_override('starting', 0)
+  call test_override('char_avail', 0)
   bwipe!
 endfunc
 

src/testdir/test_mapping.vim

@@ -1453,6 +1453,7 @@ func Test_map_script_cmd_survives_unmap()
 
   nunmap <F3>
   unlet b:result
+  autocmd! CmdlineEnter
 endfunc
 
 " Test for using <script> with a map to remap characters in rhs

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    4149,
 /**/
     4148,
 /**/