[llvm] r209007 - Fix most of PR10367.

[Rafael Espíndola]

> I don’t think it’s a bad practice to open bugs with design issues, I just think
> that you should not treat that as a substitute for a detailed proposal sent
> to llvm-dev.  Including a link to the PR saying “we’ve talked about it a lot
> here” is fine.  Telling me that, in order to have an opinion on IR design,
> I need to keep up with llvm-commits, the entire bug tracker, and your personal
> discussions with Chris at the developers’ conference is not okay.

I keep to saying that in the years this has been up you should have
been able to noticed it and that is a reasonable expectation.

It also seems you are holding me to a higher standard than yourself.
If you started to use a feature that we could not ever stream
correctly via bitcode and we have a bug about dropping. It seems you
are the one that would have the much higher burden of proposing a
change: geps with non zero offsets.

> Here's an obvious one: a global alias to a ConstantInt (maybe inttoptr’ed)
> is a really natural way to express an absolute symbol.

Or an offset from null. I quiet like the feature. I will try to come
up with a patch for it once the current one is done.

Cheers,
Rafael