Revert "Revert "ART: Do not eagerly type LoopPhi [null, ...]""

Fixes one more place where RTP expected the parent to have valid RTI.

This reverts commit 5f3fb18e9705f7d0d594f665858bff2020409c6a.

Bug: 25899441
Change-Id: I65c55a81617ffb82c2de2470eda562600b10d479
3 files changed