Move common identifiers, names and selectors to a separate library.

pkg/compiler/lib/src/inferrer/closure_tracer.dart

Index: pkg/compiler/lib/src/inferrer/closure_tracer.dart
diff --git a/pkg/compiler/lib/src/inferrer/closure_tracer.dart b/pkg/compiler/lib/src/inferrer/closure_tracer.dart
index 262f652c8e9b52700739efc601d09d49984c1ed0..aa780019e9329697e9f0048db53f3a720a555147 100644
--- a/pkg/compiler/lib/src/inferrer/closure_tracer.dart
+++ b/pkg/compiler/lib/src/inferrer/closure_tracer.dart
@@ -101,7 +101,7 @@ class ClosureTracerVisitor extends TracerVisitor<ApplyableTypeInformation> {
         registerCallForLaterAnalysis(info);
       }
     } else if (info.selector.isGetter &&
-        info.selector.name == Compiler.CALL_OPERATOR_NAME) {
+        info.selector.memberName == Names.call) {
       // We are potentially tearing off ourself here
       addNewEscapeInformation(info);
     }