- Create frame work for adding read only handles for symbols in the VM isolate

vm/dart_api_impl.cc

Index: vm/dart_api_impl.cc
===================================================================
--- vm/dart_api_impl.cc	(revision 15861)
+++ vm/dart_api_impl.cc	(working copy)
@@ -2745,8 +2745,7 @@
     // Case 4.  Lookup the function with a . appended to find the
     // unnamed constructor.
     if (func.IsNull()) {
-      const String& dot = String::Handle(Symbols::Dot());
-      tmp_name = String::Concat(func_name, dot);
+      tmp_name = String::Concat(func_name, Symbols::DotHandle());
       func = cls.LookupFunction(tmp_name);
     }
   } else if (obj.IsLibrary()) {
@@ -3313,8 +3312,7 @@
   if (name_obj.IsNull()) {
     dot_name = Symbols::Dot();
   } else if (name_obj.IsString()) {
-    const String& dot = String::Handle(isolate, Symbols::Dot());
-    dot_name = String::Concat(dot, String::Cast(name_obj));
+    dot_name = String::Concat(Symbols::DotHandle(), String::Cast(name_obj));
   } else {
     RETURN_TYPE_ERROR(isolate, constructor_name, String);
   }