VM: Replace StoreVMField with StoreInstanceField.

runtime/vm/il_printer.cc

Index: runtime/vm/il_printer.cc
===================================================================
--- runtime/vm/il_printer.cc	(revision 33058)
+++ runtime/vm/il_printer.cc	(working copy)
@@ -420,9 +420,13 @@
 
 
 void StoreInstanceFieldInstr::PrintOperandsTo(BufferFormatter* f) const {
-  f->Print("%s {%" Pd "}, ",
-           String::Handle(field().name()).ToCString(),
-           field().Offset());
+  if (field().IsNull()) {
+    f->Print("{%" Pd "}, ", offset_in_bytes());
+  } else {
+    f->Print("%s {%" Pd "}, ",
+             String::Handle(field().name()).ToCString(),
+             field().Offset());
+  }
   instance()->PrintTo(f);
   f->Print(", ");
   value()->PrintTo(f);
@@ -530,13 +534,6 @@
 }
 
 
-void StoreVMFieldInstr::PrintOperandsTo(BufferFormatter* f) const {
-  dest()->PrintTo(f);
-  f->Print(", %" Pd ", ", offset_in_bytes());
-  value()->PrintTo(f);
-}
-
-
 void InstantiateTypeInstr::PrintOperandsTo(BufferFormatter* f) const {
   const String& type_name = String::Handle(type().Name());
   f->Print("%s, ", type_name.ToCString());