3 further backports to 6.3

[Richard Biener]

On Fri, 9 Dec 2016, Jakub Jelinek wrote:

> Hi!
> 
> My tree-ssa-reassoc.c fix backport for 6 branch depends on 2 other patches,
> where the testcases don't fail on the branch for those 2, but the issue has
> been just latent.  Are these ok to backport to 6.3 too?

Yes.

Thanks,
Richard.