[boehm-gc] Import 6.3 alpha 1

[Tom Tromey]

Jeff> Exactly.  And java developers in general don't care about
Jeff> correctness; just making something run with the JRE is good
Jeff> enough for them.

Yeah.  Sigh.

Jeff> While we're on the topic:  a major goal I'd like to see come from this
Jeff> binary compatibility work is to eliminate the "duplicate class
Jeff> registration" error.  Don't allow it to happen, ever.

Yes, definitely.  At least for code using the binary compatible ABI.
I'd still like to see it be possible to generate hard references to
everything like we do now.  In that situation the error still has
meaning, but the idea is that this would only be used in special
situations.

Tom