tree-optimization/113796 - if-conversion and ranges

The following makes sure to wipe range info before folding the
COND_EXPRs we insert as part of replacing PHI nodes when combining
blocks in the if-conversion pass.

	PR tree-optimization/113796
	* tree-if-conv.cc (combine_blocks): Wipe range-info before
	replacing PHIs and inserting predicates.

	* gcc.dg/torture/pr113796.c: New testcase.
2 files changed