patch 9.0.0360: crash when invalid line number on :for is ignored

Problem:    Crash when invalid line number on :for is ignored.
Solution:   Do not check breakpoint for non-existing line.

src/testdir/test_eval_stuff.vim

@@ -1,6 +1,7 @@
 " Tests for various eval things.
 
 source view_util.vim
+source shared.vim
 
 function s:foo() abort
   try
@@ -87,6 +88,18 @@ func Test_for_over_null_string()
   let &enc = save_enc
 endfunc
 
+func Test_for_invalid_line_count()
+  let lines =<< trim END
+      111111111111111111111111 for line in ['one']
+      endfor
+  END
+  call writefile(lines, 'XinvalidFor')
+  " only test that this doesn't crash
+  call RunVim([], [], '-u NONE -e -s -S XinvalidFor -c qa')
+
+  call delete('XinvalidFor')
+endfunc
+
 func Test_readfile_binary()
   new
   call setline(1, ['one', 'two', 'three'])