Background compilation fixes

runtime/vm/object.cc

Index: runtime/vm/object.cc
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index fe8f2ceb8f890231ce4a5a3f377fa0c729273c29..0f2b324179effa9eead4e186d9d46bd8eb43beb4 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -13533,20 +13533,21 @@ const char* Code::ToCString() const {
 }
 
 
+// Called by disassembler.
 RawString* Code::Name() const {
   const Object& obj = Object::Handle(owner());
   if (obj.IsNull()) {
     // Regular stub.
     const char* name = StubCode::NameOfStub(EntryPoint());
     ASSERT(name != NULL);
-    const String& stub_name = String::Handle(String::New(name));
-    return String::Concat(Symbols::StubPrefix(), stub_name);
+    const String& stub_name = String::Handle(Symbols::New(name));
+    return Symbols::FromConcat(Symbols::StubPrefix(), stub_name);
   } else if (obj.IsClass()) {
     // Allocation stub.
     const Class& cls = Class::Cast(obj);
     String& cls_name = String::Handle(cls.Name());
     ASSERT(!cls_name.IsNull());
-    return String::Concat(Symbols::AllocationStubFor(), cls_name);
+    return Symbols::FromConcat(Symbols::AllocationStubFor(), cls_name);
   } else {
     ASSERT(obj.IsFunction());
     // Dart function.