ssair: fix phi edge cleanup for current block
When removing an edge during compaction, phi pruning treated only blocks\nwith to < active_bb as already compacted. If the edge was removed into\nthe current block, its phi nodes had already been rewritten with renamed\npredecessors, but the cleanup path still searched using the old\npredecessor ID in the pre-compact IR. This left a live block with a phi\nedge from a dead predecessor and broke IR verification.\n\nTreat to == active_bb as already compacted so phi edges are removed from\nthe result stream with renamed predecessor IDs.
