Fix pretty-printer test failure by carrying the bound lifetime names through
the types. Initially I thought it would be necessary to thread this data
through not only the AST but the types themselves, but then I remembered that
the pretty printer only cares about the AST. Regardless, I have elected to
leave the changes to the types intact since they will eventually be needed. I
left a few FIXMEs where it didn't seem worth finishing up since the code wasn't
crucial yet.