Get syntax errors/invalid colorization on project load when you've customized the version

[davkean]

When you've customized the language version, or you have a restored document with a #if DEBUG (and DEBUG is the active configuration), you get wrong colorization in source files, or get incorrect syntax errors in the error list:

This is because correct conditional constants and language version only gets set once a design-time build has completed. We should fix that and set all parse options up-front and during evaluation.