Implement simple switch statements as nested if/else.

tests/compiler/dart2js_native/dart2js_native.status

 # Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 [ $browser ]
 *: Skip
 
 [ $compiler == dart2js ]
 bound_closure_super_test: Fail
 call_on_native_class_test: CompileTimeError # Issue 14813
 native_no_such_method_exception4_frog_test: CompileTimeError # Issue 9631
 native_no_such_method_exception5_frog_test: CompileTimeError # Issue 9631
 
 [ $compiler == dart2js ]
 fake_thing_test: Fail # Issue 13010
 
 [ $compiler == dart2js && $minified ]
 optimization_hints_test: Fail, OK # Test relies on unminified names.
 
 [ $compiler == dart2js && $runtime == d8 && $system == windows ]
 compute_this_script_test: Skip # Issue 17458
 
 [ $compiler == dart2js && $cps_ir ]
 compute_this_script_test: RuntimeError # receiver.get$_collection$_nums is not a function
 event_loop_test: Crash # (try {return f(arg1,arg2);}finally {Zone._leave(old);}): try/finally
 inference_of_helper_methods_test: RuntimeError # Please triage this failure.
 internal_library_test: RuntimeError # receiver.get$_collection$_nums is not a function
-mirror_intercepted_field_test: Crash # (switch (type){case ...  Unhandled node
+mirror_intercepted_field_test: Crash # (try {return f(arg1,arg2);}finally {Zone._leave(old);}): try/finally
 native_closure_identity_frog_test: RuntimeError # invoke is not a function
 native_exception2_test: RuntimeError # Please triage this failure.
 native_exception_test: RuntimeError # J.getInterceptor(...).toString$0 is not a function
 native_method_inlining_test: RuntimeError # Please triage this failure.
-native_mirror_test: Crash # (switch (type){case ...  Unhandled node
+native_mirror_test: Crash # (try {return f(arg1,arg2);}finally {Zone._leave(old);}): try/finally
 native_mixin_field_test: RuntimeError # Please triage this failure.
 native_mixin_with_plain_test: RuntimeError # Please triage this failure.
 native_no_such_method_exception3_frog_test: RuntimeError # Please triage this failure.
 native_wrapping_function3_frog_test: RuntimeError # invoke is not a function
 native_wrapping_function_frog_test: RuntimeError # invoke is not a function
 optimization_hints_test: RuntimeError # Please triage this failure.
 rti_only_native_test: Crash # (try {map.values.for...  try/finally
 static_methods_test: RuntimeError # invoke is not a function
 subclassing_constructor_1_test: RuntimeError # Please triage this failure.
 subclassing_constructor_2_test: RuntimeError # Please triage this failure.
 subclassing_super_call_test: RuntimeError # this.get$afield is not a function
 subclassing_super_field_1_test: RuntimeError # Please triage this failure.
 subclassing_super_field_2_test: RuntimeError # Please triage this failure.
 super_call_test: RuntimeError # this.bar$0 is not a function