That's already been requested and declined in #767961: we are already too late for 0.9.3 in jessie, we need to decide whether 0.8 in jessie + 1.0 (expected soon) in jessie-backports is better or worse than just 1.0 in jessie-backports.Please unblock package beignet
While that's probably true if you mean 'make 0.8 work with llvm 3.5', llvm 3.4 isn't being removed from jessie, it just isn't the default any more. I strongly suspect that #768691 is the same bug as #767387, which can be fixed by explicitly requesting 3.4: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=767387#34Backporting the relevant changes is unfeasible,
(Please don't upload that, it doesn't fix #768090 yet.)