re PR tree-optimization/22037 (internal compiler error: verify_ssa failed)

re PR tree-optimization/22037 (internal compiler error: verify_ssa failed)

	PR 22037
	* tree-cfg.c (replace_uses_by): Call mark_new_vars_to_rename.
	(tree_merge_blocks): Propagate anything allowed by
	may_propagate_copy.
	Clarify documentation.
	* passes.c (execute_todo): If cleanup_tree_cfg invalidated the
	SSA form, schedule an update if necessary.

testsuite/ChangeLog

	PR 22037
	* g++.dg/tree-ssa/pr22037.C:

From-SVN: r102740