First part of new ICData infrastructure: use a wrapper object instead of an array.

runtime/vm/object.h

Index: runtime/vm/object.h
===================================================================
--- runtime/vm/object.h	(revision 4412)
+++ runtime/vm/object.h	(working copy)
@@ -159,6 +159,7 @@
     kLanguageErrorClass,
     kUnhandledExceptionClass,
     kUnwindErrorClass,
+    kICDataClass,
     kMaxId,
     kInvalidIndex = -1,
   };
@@ -297,6 +298,7 @@
     return unhandled_exception_class_;
   }
   static RawClass* unwind_error_class() { return unwind_error_class_; }
+  static RawClass* icdata_class() { return icdata_class_; }
 
   static int GetSingletonClassIndex(const RawClass* raw_class);
   static RawClass* GetSingletonClass(int index);
@@ -403,6 +405,7 @@
   static RawClass* language_error_class_;  // Class of LanguageError.
   static RawClass* unhandled_exception_class_;  // Class of UnhandledException.
   static RawClass* unwind_error_class_;  // Class of UnwindError.
+  static RawClass* icdata_class_;  // Class of ICData.
 
   friend void RawObject::Validate() const;
   friend class SnapshotReader;
@@ -2085,10 +2088,6 @@
     StorePointer(&raw_ptr()->var_descriptors_, value.raw());
   }
 
-  // See class ICData for interpretation of the 'ic_data_' array.
-  RawArray* ic_data() const;
-  void set_ic_data(const Array& ic_data) const;
-
   RawExceptionHandlers* exception_handlers() const {
     return raw_ptr()->exception_handlers_;
   }
@@ -2131,8 +2130,9 @@
   bool ObjectExistInArea(intptr_t start_offest, intptr_t end_offset) const;
 
   // Each (*node_ids)[n] has a an extracted ic data array (*arrays)[n].
-  void ExtractIcDataArraysAtCalls(GrowableArray<intptr_t>* node_ids,
-                                  GrowableArray<const Array*>* arrays) const;
+  void ExtractIcDataArraysAtCalls(
+      GrowableArray<intptr_t>* node_ids,
+      GrowableArray<const ICData*>* ic_data_objs) const;
 
  private:
   static const intptr_t kEntrySize = sizeof(int32_t);  // NOLINT
@@ -3612,6 +3612,74 @@
 };
 
 
+// Object holding information about an IC: test classes and their
+// corresponding classes.
+class ICData : public Instance {
+ public:
+  RawFunction* function() const {
+    return raw_ptr()->function_;
+  }
+
+  RawString* target_name() const {
+    return raw_ptr()->target_name_;
+  }
+
+  RawArray* ic_data() const {
+    return raw_ptr()->ic_data_;
+  }
+
+  intptr_t num_args_tested() const {
+    return raw_ptr()->num_args_tested_;
+  }
+
+  intptr_t id() const {
+    return raw_ptr()->id_;
+  }
+
+  intptr_t NumberOfChecks() const;
+
+  static intptr_t InstanceSize() {
+    return RoundedAllocationSize(sizeof(RawICData));
+  }
+
+  static intptr_t target_name_offset() {
+    return OFFSET_OF(RawICData, target_name_);
+  }
+
+  static intptr_t num_args_tested_offset() {
+    return OFFSET_OF(RawICData, num_args_tested_);
+  }
+
+  static intptr_t ic_data_offset() {
+    return OFFSET_OF(RawICData, ic_data_);
+  }
+
+  void AddCheck(const GrowableArray<const Class*>& classes,
+                const Function& target) const;
+  void GetCheckAt(intptr_t index,
+                  GrowableArray<const Class*>* classes,
+                  Function* target) const;
+  void GetOneClassCheckAt(int index, Class* cls, Function* target) const;
+
+  static RawICData* New(const Function& caller_function,
+                        const String& target_name,
+                        intptr_t id,
+                        intptr_t num_args_tested);
+
+ private:
+  void set_function(const Function& value) const;
+  void set_target_name(const String& value) const;
+  void set_id(intptr_t value) const;
+  void set_num_args_tested(intptr_t value) const;
+  void set_ic_data(const Array& value) const;
+
+  intptr_t TestEntryLength() const;
+
+  HEAP_OBJECT_IMPLEMENTATION(ICData, Instance);
+  friend class Class;
+};
+
+
 // Breaking cycles and loops.
 RawClass* Object::clazz() const {
   uword raw_value = reinterpret_cast<uword>(raw_);