Analysis doesn't re-trigger when buffer is changed with `.`

[fishythefish]

Running into this issue with https://github.com/dart-lang/dart-vim-plugin + Dart Analysis Server, but I'm not sure if it's a general issue.

Concrete example:

void main() {
  var x = 1;
  var y = 2;
  x = 3.0;
  y = 4.0;
}

Dart Analyzer issues two diagnostics here. If I navigate to the first var and cwnum<ESC> in Vim, it fixes the first one. If I then navigate to the second var and hit ., Analyzer doesn't respond to the buffer change. I have to enter and exit insert mode or perform another action like pasting, reformatting, etc. in order to re-trigger it.