A few simple cleanups.

runtime/vm/intermediate_language.h

Index: runtime/vm/intermediate_language.h
diff --git a/runtime/vm/intermediate_language.h b/runtime/vm/intermediate_language.h
index f881959c66c3365f9fab522ec13e37ba22c566a0..20d201203ac356d708712f01fe6d210e485aee37 100644
--- a/runtime/vm/intermediate_language.h
+++ b/runtime/vm/intermediate_language.h
@@ -1070,7 +1070,6 @@ class BlockEntryInstr : public Instruction {
 
   virtual intptr_t PredecessorCount() const = 0;
   virtual BlockEntryInstr* PredecessorAt(intptr_t index) const = 0;
-  virtual void PrepareEntry(FlowGraphCompiler* compiler) = 0;
 
   intptr_t preorder_number() const { return preorder_number_; }
   void set_preorder_number(intptr_t number) { preorder_number_ = number; }
@@ -1292,8 +1291,6 @@ class GraphEntryInstr : public BlockEntryInstr {
 
   CatchBlockEntryInstr* GetCatchEntry(intptr_t index);
 
-  virtual void PrepareEntry(FlowGraphCompiler* compiler);
-
   GrowableArray<Definition*>* initial_definitions() {
     return &initial_definitions_;
   }
@@ -1359,8 +1356,6 @@ class JoinEntryInstr : public BlockEntryInstr {
 
   ZoneGrowableArray<PhiInstr*>* phis() const { return phis_; }
 
-  virtual void PrepareEntry(FlowGraphCompiler* compiler);
-
   void InsertPhi(intptr_t var_index, intptr_t var_count);
   void RemoveDeadPhis(Definition* replacement);
 
@@ -1429,8 +1424,6 @@ class TargetEntryInstr : public BlockEntryInstr {
     return predecessor_;
   }
 
-  virtual void PrepareEntry(FlowGraphCompiler* compiler);
-
   virtual void PrintTo(BufferFormatter* f) const;
 
  private:
@@ -1478,8 +1471,6 @@ class CatchBlockEntryInstr : public BlockEntryInstr {
     return &initial_definitions_;
   }
 
-  virtual void PrepareEntry(FlowGraphCompiler* compiler);
-
   virtual void PrintTo(BufferFormatter* f) const;
 
  private: