ifcvt/crossjump patch: Fix PR 42496, 21803

[Eric Botcazou]

> It's probably worth noting that these optimizations are more effective
> when they're allowed to move insns.   So while limiting to CFG
> approaches may simplify things, it also leads to fewer opportunities to
> commonize code.

Do you have a concrete example of such an optimization that would be doable 
with code movements but not with CFG manipulations?

-- 
Eric Botcazou