Remove the concept of a "nonsettable lvalue": Now everything that is

nonsettable is represented as an rvalue.  Yay for one less concept in
the AST.


Swift SVN r11640

lib/Serialization/Serialization.cpp

@@ -1793,8 +1793,7 @@ void Serializer::writeType(Type ty) {
     unsigned abbrCode = DeclTypeAbbrCodes[LValueTypeLayout::Code];
     LValueTypeLayout::emitRecord(Out, ScratchRecord, abbrCode,
                                  addTypeRef(lValueTy->getObjectType()),
-                                 lValueTy->getQualifiers().isImplicit(),
-                                 !lValueTy->getQualifiers().isSettable());
+                                 lValueTy->getQualifiers().isImplicit());
     break;
   }