Support upcoming Scala 3 indentation-based syntax in Scala 2.13

[eyalroth]

@jvican

Scala 3’s new indentation-based syntax has been in the making for the past half a year. I think it’s an interesting change and I’d like to give it a try in my medium-sized codebases. However, this is not possible today, because to try the new syntax I need to use Scala 3’s Dotty compiler.

Is this possible to implement via a compiler plugin or is it too fundamental?