Add proper API for creating private symbols wrt a library.

tests/lib/lib.status

Index: tests/lib/lib.status
diff --git a/tests/lib/lib.status b/tests/lib/lib.status
index e351e77444d5f0c9d9efe5d4783016dc5f5e8769..90dbc1a24599c33a169a8251d7d32400707c8713 100644
--- a/tests/lib/lib.status
+++ b/tests/lib/lib.status
@@ -11,6 +11,8 @@ mirrors/fake_function_test: RuntimeError # Issue 11612
 mirrors/function_type_mirror_test: RuntimeError # Issue 12166
 mirrors/generics_test/01: RuntimeError # Issue 12333
 mirrors/hierarchy_invariants_test: RuntimeError # Issue 11863
+mirrors/intercepted_class_test: RuntimeError # Issue 13644

[rmacnak, 2013/09/27 01:38:27]

Not sure if there is anything to split out for partial coverage.

+mirrors/intercepted_object_test: RuntimeError # Issue 13644
 mirrors/invoke_test: RuntimeError # Issue 11954
 mirrors/invoke_closurization_test: RuntimeError # Issue 13002
 mirrors/invoke_named_test/none: RuntimeError # Issue 12863
@@ -37,7 +39,8 @@ async/run_async6_test: RuntimeError # global error handling is not supported. ht
 mirrors/typedef_test/none: RuntimeError # http://dartbug.com/6490
 mirrors/redirecting_factory_test/none: RuntimeError # Issue 6490
 mirrors/redirecting_factory_test/02: RuntimeError # Issue 6490
-mirrors/closures_test/none: RuntimeError # Issue 6490
+mirrors/symbol_validation_test: RuntimeError # Issue 13597
+mirrors/private_symbol_test: CompileTimeError # Issue 13597
 
 [ $runtime == safari ]
 mirrors/return_type_test: Pass, Timeout # Issue 12858
@@ -139,7 +142,7 @@ mirrors/typedef_test/01: Fail, OK # Incorrect dart2js behavior.
 mirrors/redirecting_factory_test/none: Fail # Issue 13365
 mirrors/redirecting_factory_test/01: Fail # Issue 13365
 mirrors/redirecting_factory_test/02: Fail # Issue 13365
-mirrors/closures_test/01: Fail, OK # Incorrect dart2js behavior.
+mirrors/symbol_validation_test: RuntimeError # Issue 13596
 
 [ $compiler == none && $runtime == drt ]
 async/timer_isolate_test: Skip # See Issue 4997