vim-patch:9.0.2111: [security]: overflow in get_number

Problem:  [security]: overflow in get_number
Solution: Return 0 when the count gets too large

[security]: overflow in get_number

When using the z= command, we may overflow the count with values larger
than MAX_INT. So verify that we do not overflow and in case when an
overflow is detected, simply return 0

73b2d3790c

Co-authored-by: Christian Brabandt <cb@256bit.org>

test/old/testdir/test_spell.vim

@@ -1081,6 +1081,15 @@ func Test_spell_compatible()
   call StopVimInTerminal(buf)
 endfunc
 
+func Test_z_equal_with_large_count()
+  split
+  set spell
+  call setline(1, "ff")
+  norm 0z=337203685477580
+  set nospell
+  bwipe!
+endfunc
+
 let g:test_data_aff1 = [
       \"SET ISO8859-1",
       \"TRY esianrtolcdugmphbyfvkwjkqxz-\xEB\xE9\xE8\xEA\xEF\xEE\xE4\xE0\xE2\xF6\xFC\xFB'ESIANRTOLCDUGMPHBYFVKWJKQXZ",