Store canonical type argments in a hash table instead of linear list.

runtime/vm/object.h

Index: runtime/vm/object.h
===================================================================
--- runtime/vm/object.h	(revision 15892)
+++ runtime/vm/object.h	(working copy)
@@ -986,6 +986,8 @@
 
   static RawTypeArguments* New(intptr_t len, Heap::Space space = Heap::kOld);
 
+  intptr_t Hash() const;

[regis, 2012/12/11 01:37:15]

You should add a Hash() to AbstractType as well (and to Type and TypeParameter),
since the hash of this vector depends on the hash of its type elements.

[Florian Schneider, 2012/12/11 12:23:04]

Done.

+
  private:
   RawAbstractType** TypeAddr(intptr_t index) const;
   void SetLength(intptr_t value) const;