Make identical(a,b) a compile-time constant in dart2js.

tests/language/language.status

Index: tests/language/language.status
diff --git a/tests/language/language.status b/tests/language/language.status
index 672df756f99a0835e3594f95277bc9f413e3d043..46e461b508646e05dddd1317eb3748ccbf5f90fc 100644
--- a/tests/language/language.status
+++ b/tests/language/language.status
@@ -70,6 +70,8 @@ lazy_static3_test: Fail # Issue 3558
 *dartc_test: Skip
 *dartc_negative_test: Skip
 
+compile_time_constant10_test: Fail # issue 5214
+
 [ $compiler == none && $mode == debug ]
 gc_test: Skip  # Takes too long.
 
@@ -156,6 +158,7 @@ class_literal_test/27 : Fail # language change 3368
 class_literal_test/28 : Fail # language change 3368
 class_literal_test/29 : Fail # language change 3368
 closure_call_wrong_argument_count_negative_test: Fail # Runtime only test, rewrite as multitest
+compile_time_constant10_test: Fail # issue 5215.
 constructor3_negative_test: Fail # Runtime only test, rewrite as multitest
 constructor_call_wrong_argument_count_negative_test: Fail # Runtime only test, rewrite as multitest
 disable_privacy_test: Fail # Issue 1882: Needs --disable_privacy support.