Implement class hierarchy analysis in the VM.

runtime/vm/class_table.h

Index: runtime/vm/class_table.h
===================================================================
--- runtime/vm/class_table.h	(revision 11005)
+++ runtime/vm/class_table.h	(working copy)
@@ -12,8 +12,11 @@
 namespace dart {
 
 class Class;
+class Function;
+template <typename T> class ZoneGrowableArray;
 class ObjectPointerVisitor;
 class RawClass;
+class String;
 
 class ClassTable {
  public:
@@ -35,6 +38,22 @@
 
   void Print();
 
+  // Returns an array containing the cids of the direct and indirect subclasses
+  // of the class given by its cid.
+  // Must not be called for kDartObjectCid.
+  ZoneGrowableArray<intptr_t>* GetSubclassIdsOf(intptr_t cid) const;
+
+  // Returns an array containing instance functions of the given name and
+  // belonging to the classes given by their cids.
+  // Cids must not contain kDartObjectCid.
+  ZoneGrowableArray<Function*>* GetNamedInstanceFunctionsOf(
+      const ZoneGrowableArray<intptr_t>& cids,
+      const String& function_name) const;
+
+  // Returns an array of functions overriding the given function.
+  // Must not be called for a function of class Object.
+  ZoneGrowableArray<Function*>* GetOverridesOf(const Function& function) const;
+
   static intptr_t table_offset() {
     return OFFSET_OF(ClassTable, table_);
   }