php8: fixed a bug with # comments (#22)

Example from issue:
```php
<?php
#
# Comment
#

$a = 100;
```

The problem with the example from the issue is that `#` is immediately followed by a line break.
And since the rule in the lexer for such comments was changed, this case was handled incorrectly.

```
(('#' ^'[') | '//') any_line* when is_not_comment_end => {
   lex.ungetStr("?>")
   lex.addFreeFloatingToken(tkn, token.T_COMMENT, lex.ts, lex.te)
};
```

This rule has one problem, it checks two characters at once, first for the match `#`, and 
then for the mismatch `[`, which leads to the fact that in the case of an empty comment, the first 
matcher will capture `#`, and the second line break (`\n`), which will lead to the fact that `any_line` 
matcher will not work and will not increase the line number.

The next rule added is specifically for this case.

```
'#' newline when is_not_comment_end => {
    lex.ungetStr("?>")
    lex.addFreeFloatingToken(tkn, token.T_COMMENT, lex.ts, lex.te)
};
```

internal/tester/lexer_token_struct.go

@@ -18,6 +18,9 @@ type LexerTokenStructTestSuite struct {
 	Expected []*token.Token
 
 	Version version.Version
+
+	withPosition     bool
+	withFreeFloating bool
 }
 
 func NewLexerTokenStructTestSuite(t *testing.T) *LexerTokenStructTestSuite {
@@ -34,6 +37,14 @@ func (l *LexerTokenStructTestSuite) UsePHP8() {
 	l.Version = version.Version{Major: 8, Minor: 0}
 }
 
+func (l *LexerTokenStructTestSuite) WithPosition() {
+	l.withPosition = true
+}
+
+func (l *LexerTokenStructTestSuite) WithFreeFloating() {
+	l.withFreeFloating = true
+}
+
 func (l *LexerTokenStructTestSuite) Run() {
 	config := conf.Config{
 		Version: &l.Version,
@@ -49,8 +60,12 @@ func (l *LexerTokenStructTestSuite) Run() {
 
 	for _, expected := range l.Expected {
 		actual := lexer.Lex()
-		actual.Position = nil
-		actual.FreeFloating = nil
+		if !l.withPosition {
+			actual.Position = nil
+		}
+		if !l.withFreeFloating {
+			actual.FreeFloating = nil
+		}
 		assert.DeepEqual(l.t, expected, actual)
 	}
 }