re PR tree-optimization/70724 (Miscompiles python3 with FDO)

re PR tree-optimization/70724 (Miscompiles python3 with FDO)

2016-04-19  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/70724
	* tree-ssa-sccvn.c (scc_vn_restore_ssa_info): Split SSA info
	restoring out from ...
	(free_scc_vn): ... here.
	* tree-ssa-sccvn.h (scc_vn_restore_ssa_info): Declare.
	* tres-ssa-pre.c (pass_pre::execute): Restore SSA info before
	tail merging.
	(pass_fre::execute): Restore SSA info.

	* gcc.dg/torture/pr70724.c: New testcase.

From-SVN: r235203