[Bug tree-optimization/66522] handle casts in nr of iterations in try_transform_to_exit_first_loop_alt

[vries at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66522

--- Comment #4 from vries at gcc dot gnu.org ---
(In reply to vries from comment #3)
> New patch: https://gcc.gnu.org/ml/gcc-patches/2015-06/msg02085.html

Pinged: https://gcc.gnu.org/ml/gcc-patches/2015-07/msg00729.html