vim-patch:8.2.1383: test 49 is old style

Problem:    Test 49 is old style.
Solution:   Convert test cases to new style. (Yegappan Lakshmanan,
            closes vim/vim#6638)

9470a4d88a

Cherry-pick AssertException() from patch 8.2.1146.

src/nvim/testdir/shared.vim

@@ -364,4 +364,19 @@ func GetMessages()
   return msg_list
 endfunc
 
+" Run the list of commands in 'cmds' and look for 'errstr' in exception.
+" Note that assert_fails() cannot be used in some places and this function
+" can be used.
+func AssertException(cmds, errstr)
+  let save_exception = ''
+  try
+    for cmd in a:cmds
+      exe cmd
+    endfor
+  catch
+    let save_exception = v:exception
+  endtry
+  call assert_match(a:errstr, save_exception)
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab

src/nvim/testdir/test49.ok

@@ -1,18 +1,9 @@
 Results of test49.vim:
-*** Test  52: OK (1247112011)
-*** Test  53: OK (131071)
-*** Test  54: OK (2047)
-*** Test  55: OK (1023)
-*** Test  56: OK (511)
-*** Test  57: OK (2147450880)
-*** Test  58: OK (624945)
 *** Test  59: OK (2038431743)
 *** Test  60: OK (311511339)
-*** Test  61: OK (374889517)
 *** Test  62: OK (286331153)
 *** Test  63: OK (236978127)
 *** Test  64: OK (1499645335)
-*** Test  65: OK (70187)
 *** Test  66: OK (5464)
 *** Test  67: OK (212514423)
 *** Test  68: OK (212514423)