Copy propagated type info when inserting conversion.

runtime/vm/intermediate_language.h

Index: runtime/vm/intermediate_language.h
===================================================================
--- runtime/vm/intermediate_language.h	(revision 18669)
+++ runtime/vm/intermediate_language.h	(working copy)
@@ -224,13 +224,13 @@
     Value* next_;
   };
 
-  explicit Value(Definition* definition)
+  explicit Value(Definition* definition, CompileType* type = NULL)

[srdjan, 2013/02/19 16:51:47]

Why the optional argument? We really should avoid them.

       : definition_(definition),
         previous_use_(NULL),
         next_use_(NULL),
         instruction_(NULL),
         use_index_(-1),
-        reaching_type_(NULL) { }
+        reaching_type_(type) { }
 
   Definition* definition() const { return definition_; }
   void set_definition(Definition* definition) { definition_ = definition; }
@@ -252,6 +252,10 @@
 
   Value* Copy() { return new Value(definition_); }
 
+  // This function must only be used when the new Value is dominated by
+  // the original Value.
+  Value* CopyWithType() { return new Value(definition_, reaching_type_); }
+
   CompileType* Type();
 
   void SetReachingType(CompileType* type) {