RUNPATH/LD_LIBRARY_PATH Fixes

[bholt]

Using RUNPATH again, and should be prepending LD_LIBRARY_PATH correctly, but doesn't solve the problem of being able to specify libs like we wanted to do on Pal, because whatever's in LD_LIBRARY_PATH will still be prepended by srun_prolog.

This solution is, first of all, pretty messy as it involves now hardcoding the lib path in the run script, but still doesn't allow us to point at different libraries dynamically.

@nelsonje: Any ideas about how to do this better?

[bholt]

Oh, and I also was just looking at how igor_common isolates exes, and I can't see anywhere where I'm actually changing LD_LIBRARY_PATH. So now I'm wondering if it's even been using the copied libraries, or whether it has still been loading them from where they were this whole time...

[bholt]

(btw, I think this need not hold up flipping the bit, it's definitely an edge case)

[bholt]

@nelsonje @bmyerz: I've gotten LD_LIBRARY_PATH working again, with Igor isolation. I also fixed the segfault failure problems I was seeing, so we're now using Glog to generate backtraces, and calling Gasnet suspend if "--freeze-on-error" is specified.

[bholt]

Let me know if you think it's alright to merge into master.

[nelsonje]

This will disappear, right? :-)

[bholt]

Hmm, actually it looks like this didn't completely solve the problem: now Gasnet freeze works for segfaults, but not for assertion failures.