re PR tree-optimization/46107 (-ftree-loop-distribute-patterns caused verify_loop_structure problem)

	PR tree-optimization/46107
	* cfgloopmanip.c (loop_version): Set irred_flag back into entry->flags
	if cfg_hook_duplicate_loop_to_header_edge failed.

	* gcc.c-torture/compile/pr46107.c: New test.

From-SVN: r166234