Remove unused field AstNode::ic_data.

runtime/vm/ast.h

Index: runtime/vm/ast.h
diff --git a/runtime/vm/ast.h b/runtime/vm/ast.h
index a9be2622f9238ed9c7050b7d776b179b9a46878c..f3267ab5154451ec09ed535fe95cdf1c3fa57d4a 100644
--- a/runtime/vm/ast.h
+++ b/runtime/vm/ast.h
@@ -92,18 +92,12 @@ NODE_LIST(DEFINE_VISITOR_FUNCTION)
 class AstNode : public ZoneAllocated {
  public:
   explicit AstNode(intptr_t token_pos)
-      : token_pos_(token_pos),
-        ic_data_(ICData::ZoneHandle()) {
+      : token_pos_(token_pos) {
     ASSERT(token_pos_ >= 0);
   }
 
   intptr_t token_pos() const { return token_pos_; }
 
-  const ICData& ic_data() const { return ic_data_; }
-  void set_ic_data(const ICData& value) {
-    ic_data_ = value.raw();
-  }
-
 #define AST_TYPE_CHECK(type, name)                                             \
   virtual bool Is##type() const { return false; }                              \
   virtual type* As##type() { return NULL; }
@@ -148,8 +142,6 @@ NODE_LIST(AST_TYPE_CHECK)
 
  private:
   const intptr_t token_pos_;
-  // IC data collected for this node.
-  ICData& ic_data_;
   DISALLOW_COPY_AND_ASSIGN(AstNode);
 };