A slightly adjusted testcase of the PR shows my lame attempt at
fixing the issue easily breaks down. So the following implements
the full solution to sinking common asserts.
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
Richard.
2017-01-27 Richard Biener
PR tree-op
The following makes VRP deal better with the situation where the
same assertion is to be inserted on all predecessors of a BB.
That avoids the spurious array-bound warning (and enables some
optimization) when jump-threading f**ed up the CFG in such redundant
way.
(the fully "correct" way to deal
