port lint should warn on illegal variant names

[ryandesign (Ryan Carsten Schmidt)]

port lint should warn when it encounters variants whose names are not composed entirely of legal characters. I'm not sure if the list of legal characters for variant names has ever been defined anywhere before, but looking through all variant names of all ports right now, I see that they are all composed of letters A-Z and a-z, numbers 0-9, underscore and hyphen/dash, and the hyphen/dash is the only one of those that causes problems. (A variant with a hyphen/dash in the name cannot be selected.) So port lint should warn if a variant name does not match the regular expression ^[A-Za-z0-9_]+$

Related: the guide should say something about valid variant names; see #14141.

[raimue (Rainer Müller)]

Implemented in r33679.

Even though you said "warn" I implemented it as an error, as such variants are not selectable.

[ryandesign (Ryan Carsten Schmidt)]

Thank you! That's what I meant. :)

I changed the wording of the message slightly in r33680.