comments not preserved
A few weird cases I'm running into; I want to preserve comments in my file but am uncovering some bugs:

## case 1

```sh
> echo -e 'if dev then --cool\n end' | shrinko8 - - -f lua -m --no-minify-comments --no-minify-spaces --const dev true
```
expected output: `--cool`
actual output: (nothing)

```sh
> echo '--cool' | shrinko8 - - -f lua -m --no-minify-comments --no-minify-spaces
```
expected output: `--cool`
actual output: (nothing)

## case 2

test2.lua:
```lua
--[[something]]
if dev then
-- true
a=1
else
-- false
a=0
end
```

```sh
> shrinko8 test2.lua out.lua -m --no-minify-comments --no-minify-spaces --const dev true
```
In this case, the `--true`/`--false` comments are removed completely for some reason. But weirdly, this _only_ happens when the `--[[something]]` comment exists -- remove it and the behavior is fine

## case 3

test3.lua:
```lua
if dev then
-- true
a=1
else
-- false
a=0
end
```

```sh
> shrinko8 --minify --no-minify-spaces --no-minify-comments test3.lua - -f lua
if (n) e=1 else e=0
```

(expected output: comments should not be removed)