Disable timer-based context switches
In the past, we repeatedly had problems with non-deterministic allocations due to stack squeezing during context switches (Trac #4450, Trac #8611).
This patch adds +RTS -V0 -RTS as extra RUNTEST_OPTS for every single-threaded benchmark.
Is this the right place to add the flags? Should we also do this for all the other benchmarks?
Reviewers: simonmar, osa1, nomeata, O26 nofib
GHC Trac Issues: Trac #8611
Differential Revision: https://phabricator.haskell.org/D5470