Add alias disambiguation for VM fields.

runtime/vm/intermediate_language.h

Index: runtime/vm/intermediate_language.h
===================================================================
--- runtime/vm/intermediate_language.h	(revision 33416)
+++ runtime/vm/intermediate_language.h	(working copy)
@@ -4017,8 +4017,7 @@
         cls_(cls),
         arguments_(arguments),
         identity_(kUnknown),
-        closure_function_(Function::ZoneHandle()),
-        context_field_(Field::ZoneHandle()) {
+        closure_function_(Function::ZoneHandle()) {
     // Either no arguments or one type-argument and one instantiator.
     ASSERT(arguments->is_empty() || (arguments->length() == 1));
   }
@@ -4039,11 +4038,6 @@
     closure_function_ ^= function.raw();
   }
 
-  const Field& context_field() const { return context_field_; }
-  void set_context_field(const Field& field) {
-    context_field_ ^= field.raw();
-  }
-
   virtual void PrintOperandsTo(BufferFormatter* f) const;
 
   virtual bool CanDeoptimize() const { return false; }
@@ -4070,7 +4064,6 @@
   ZoneGrowableArray<PushArgumentInstr*>* const arguments_;
   Identity identity_;
   Function& closure_function_;
-  Field& context_field_;
 
   DISALLOW_COPY_AND_ASSIGN(AllocateObjectInstr);
 };
@@ -4082,7 +4075,7 @@
 class MaterializeObjectInstr : public Definition {

[srdjan, 2014/03/07 17:38:37]

Please rename 'fields' to fields_or_offsets'. Such a name can be used instead of
additional argument documentation. Also on other places as well.

[Florian Schneider, 2014/03/10 09:46:48]

Done. Renamed to 'slots' since I prefer a concise name.

  public:
   MaterializeObjectInstr(const Class& cls,
-                         const ZoneGrowableArray<const Field*>& fields,
+                         const ZoneGrowableArray<const Object*>& fields,
                          ZoneGrowableArray<Value*>* values)
       : cls_(cls), fields_(fields), values_(values), locations_(NULL) {
     ASSERT(fields_.length() == values_->length());
@@ -4094,7 +4087,9 @@
 
   const Class& cls() const { return cls_; }
   intptr_t FieldOffsetAt(intptr_t i) const {
-    return fields_[i]->Offset();
+    return fields_[i]->IsField()
+        ? Field::Cast(*fields_[i]).Offset()
+        : Smi::Cast(*fields_[i]).Value();
   }
   const Location& LocationAt(intptr_t i) {
     return locations_[i];
@@ -4135,7 +4130,7 @@
   }
 
   const Class& cls_;
-  const ZoneGrowableArray<const Field*>& fields_;
+  const ZoneGrowableArray<const Object*>& fields_;
   ZoneGrowableArray<Value*>* values_;
   Location* locations_;