Rename the VM internal 'var' type to 'Dynamic' type.

runtime/lib/error.cc

Index: runtime/lib/error.cc
===================================================================
--- runtime/lib/error.cc	(revision 778)
+++ runtime/lib/error.cc	(working copy)
@@ -194,7 +194,7 @@
   const TypeArguments& dst_type_instantiator =
       TypeArguments::CheckedHandle(arguments.At(3));
   const String& dst_name = String::CheckedHandle(arguments.At(4));
-  ASSERT(!dst_type.IsVarType());  // No need to check assignment to 'var type'.
+  ASSERT(!dst_type.IsDynamicType());  // No need to check assignment.
   ASSERT(!src_instance.IsNull());  // Already checked in inlined code.
 
   if (!src_instance.IsAssignableTo(dst_type, dst_type_instantiator)) {
@@ -258,7 +258,7 @@
   const TypeArguments& element_type_instantiator =
       TypeArguments::CheckedHandle(arguments.At(3));
   const String& rest_name = String::CheckedHandle(arguments.At(4));
-  ASSERT(!element_type.IsVarType());  // No need to check assignment.
+  ASSERT(!element_type.IsDynamicType());  // No need to check assignment.
   ASSERT(!rest_array.IsNull());
 
   Instance& elem = Instance::Handle();