re PR tree-optimization/27283 (ICE: SSA corruption - Conflict across an abnormal edge)
PR tree-optimization/27283
* tree-ssa-loop-ivopts.c (struct nfe_cache_elt): Store just trees,
not whole # of iteration descriptions.
(niter_for_exit): Return just # of iterations. Fail if # of iterations
uses abnormal ssa name.
(niter_for_single_dom_exit): Ditto.
(find_induction_variables, may_eliminate_iv): Expect niter_for_exit to
return just the number of iterations.