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

runtime/vm/object_store.cc

Index: runtime/vm/object_store.cc
===================================================================
--- runtime/vm/object_store.cc	(revision 774)
+++ runtime/vm/object_store.cc	(working copy)
@@ -125,7 +125,7 @@
   switch (index) {
     case kObjectType: return object_type();
     case kNullType: return null_type();
-    case kVarType: return var_type();
+    case kVarType: return dynamic_type();
     case kVoidType: return void_type();
     case kFunctionInterface: return function_interface();
     case kNumberInterface: return number_interface();
@@ -146,7 +146,7 @@
     return kObjectType;
   } else if (raw_type == null_type()) {
     return kNullType;
-  } else if (raw_type == var_type()) {
+  } else if (raw_type == dynamic_type()) {
     return kVarType;
   } else if (raw_type == void_type()) {
     return kVoidType;