Move isPrivateName and isPublicName to Name.

pkg/compiler/lib/src/compiler.dart

Index: pkg/compiler/lib/src/compiler.dart
diff --git a/pkg/compiler/lib/src/compiler.dart b/pkg/compiler/lib/src/compiler.dart
index 7bdf2be711d1ed1abb572b6133b7912e01e7a640..fad09bcf3048265fd81f90460e9fed3b76dcbe83 100644
--- a/pkg/compiler/lib/src/compiler.dart
+++ b/pkg/compiler/lib/src/compiler.dart
@@ -127,7 +127,6 @@ import 'universe/universe.dart' show
     CallStructure,
     Selector,
     Universe;
-import 'util/characters.dart' show $_;
 import 'util/util.dart' show
     Link;
 import 'world.dart' show
@@ -1674,12 +1673,6 @@ abstract class Compiler implements DiagnosticListener {
   }
 }
 
-/// Returns `true` when [s] is private if used as an identifier.
-bool isPrivateName(String s) => !s.isEmpty && s.codeUnitAt(0) == $_;
-
-/// Returns `true` when [s] is public if used as an identifier.
-bool isPublicName(String s) => !isPrivateName(s);
-
 /// Information about suppressed warnings and hints for a given library.
 class SuppressionInfo {
   int warnings = 0;