I can't think of any of my employers I've had in the last 15 years that would have cared that I committed code to a compiler project, with one exception. That one exception would have told me they'd rather have me work on a different product than the one I was applying to, despite the one I was applying to being more interesting to me than debugging compilers all day.

YMMV, I guess, but you're better off demonstrating experience with what they're hiring for, not random tech that they aren't and never will use.