Cleanups.

runtime/vm/intermediate_language.h

Index: runtime/vm/intermediate_language.h
===================================================================
--- runtime/vm/intermediate_language.h	(revision 9794)
+++ runtime/vm/intermediate_language.h	(working copy)
@@ -2035,6 +2035,9 @@
     predecessors_.Add(predecessor);
   }
 
+  // Returns -1 if pred is not in the list.
+  intptr_t IndexOfPredecessor(BlockEntryInstr* pred) const;
+
   ZoneGrowableArray<PhiInstr*>* phis() const { return phis_; }
 
   virtual void PrepareEntry(FlowGraphCompiler* compiler);
@@ -2044,7 +2047,7 @@
   intptr_t phi_count() const { return phi_count_; }
 
  private:
-  ZoneGrowableArray<BlockEntryInstr*> predecessors_;
+  GrowableArray<BlockEntryInstr*> predecessors_;
   ZoneGrowableArray<PhiInstr*>* phis_;
   intptr_t phi_count_;