re PR tree-optimization/88797 (Unneeded branch added when function is inlined (function runs faster if not inlined))

	PR tree-optimization/88797
	* gimple-ssa-split-paths (is_feasible_trace): Reject cases where the
	PHI feeds a conditional on the RHS of an assignment.

	PR tree-optimization/88797
	* g++.dg/tree-ssa/pr88797.C: New test.

From-SVN: r270775