libsanitizer merge from upstream r196090

[Jeff Law]

On 12/03/13 22:08, Konstantin Serebryany wrote:
> We need
> a) patches that we can review and apply to the llvm repository (w/o
> breaking the modern systems, of course)
> b) a buildbot that would run 24/7 catching regressions.
>
> If we reach a green state for a platform X and have a buildbot for it,
> keeping it green will require relatively small effort.
> Every time we break it we will notice it in minutes and fix quickly
> while we still have the same context fresh.
> Fixing old systems once in few months during merge to gcc is costly
> because failures accumulate.
I'm well overbooked already.  However, if you have x86/x86_64 systems in 
your build farm that can be virtualized, I can help set up a suitable 
VM.  CentOS 5.x is old enough to trigger lots of interesting problems, 
but is still in widespread use.

Jeff