span/lastOffset of identifier tokens is wrong when operator is directly followed by comment

[SrTobi]

Minimized code

object Main {
  def test[T] = ?//test
}

Output

Expectation

Only the ? should be underlined.

Also happens with multi line comments.

[SrTobi]

Problem is in https://github.com/lampepfl/dotty/blob/39383889e262f887c8c518a717a787cfd00e0c8f/compiler/src/dotty/tools/dotc/parsing/Scanners.scala#L967
the comment is lexed before the identifier gets finished, instead of finishing the identifier before lexing the comment