Merge "Reduce memory usage of SSA Phi elimination and make it faster."
am: d2050db7e1

* commit 'd2050db7e149549f62a02e34e967f8ea6a3d88d8':
  Reduce memory usage of SSA Phi elimination and make it faster.

Change-Id: I762fd8586457c50e164134360672bc38ffad4777