Make private symbol mangling test work on the VM, as well.

tests/lib/mirrors/private_symbol_mangling_test.dart

Index: tests/lib/mirrors/private_symbol_mangling_test.dart
diff --git a/tests/lib/mirrors/private_symbol_mangling_test.dart b/tests/lib/mirrors/private_symbol_mangling_test.dart
index 7ac0753cf1057460e133c98c59b71e5ac8125ced..ebb9371068b54c0386ae2137770eb225af557c34 100644
--- a/tests/lib/mirrors/private_symbol_mangling_test.dart
+++ b/tests/lib/mirrors/private_symbol_mangling_test.dart
@@ -21,7 +21,7 @@ class C1 {
 getPrivateGlobalFieldValue(LibraryMirror lib) {
   for (Symbol symbol in lib.declarations.keys) {
     DeclarationMirror decl = lib.declarations[symbol];
-    if (decl is VariableMirror) {
+    if (decl is VariableMirror && decl.isPrivate) {
       return lib.getField(symbol).reflectee;
     }
   }
@@ -30,7 +30,7 @@ getPrivateGlobalFieldValue(LibraryMirror lib) {
 getPrivateFieldValue(InstanceMirror cls) {
   for (Symbol symbol in cls.type.declarations.keys) {
     DeclarationMirror decl = cls.type.declarations[symbol];
-    if (decl is VariableMirror) {
+    if (decl is VariableMirror && decl.isPrivate) {
       return cls.getField(symbol).reflectee;
     }
   }
@@ -39,7 +39,7 @@ getPrivateFieldValue(InstanceMirror cls) {
 getPrivateGlobalMethodValue(LibraryMirror lib) {
   for (Symbol symbol in lib.declarations.keys) {
     DeclarationMirror decl = lib.declarations[symbol];
-    if (decl is MethodMirror && decl.isRegularMethod) {
+    if (decl is MethodMirror && decl.isRegularMethod && decl.isPrivate) {
       return lib.invoke(symbol, []).reflectee;
     }
   }
@@ -48,7 +48,7 @@ getPrivateGlobalMethodValue(LibraryMirror lib) {
 getPrivateMethodValue(InstanceMirror cls) {
   for (Symbol symbol in cls.type.declarations.keys) {
     DeclarationMirror decl = cls.type.declarations[symbol];
-    if (decl is MethodMirror && decl.isRegularMethod) {
+    if (decl is MethodMirror && decl.isRegularMethod && decl.isPrivate) {
       return cls.invoke(symbol, []).reflectee;
     }
   }