Optimize one-byte string's toUpperCase.

tests/corelib/corelib.status

 # Copyright (c) 2012, 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.
 
 [ $compiler == dart2dart]
 bool_from_environment2_test: Skip
 bool_from_environment_default_value_test: Skip
 bool_from_environment_test: Skip
 int_from_environment2_test: Skip
 int_from_environment3_test: Skip
@@ skipping 34 matching lines @@
 [ $compiler == dartanalyzer ]
 string_from_environment_test: Crash # http://dartbug.com/17234
 int_from_environment2_test: Crash # http://dartbug.com/17234
 
 [ $compiler == none ]
 unicode_test: Fail        # Bug 6706
 compare_to2_test: Fail    # Bug 4018
 
 symbol_test/01: Fail, Pass # bug 11669
 
+string_case_test/01: Fail # Bug 18061
+
 [ $compiler == none && $runtime != dartium && $runtime != drt && $runtime != ContentShellOnAndroid ]
 symbol_test/02: MissingCompileTimeError # bug 11669
 symbol_test/03: MissingCompileTimeError # bug 11669
 
 [ $compiler == none || $compiler == dart2dart ]
 symbol_test/none: Fail # bug 11669
 symbol_operator_test/03: Fail # bug 11669
 
 [ $compiler == none && ($runtime == drt || $runtime == dartium || $runtime == ContentShellOnAndroid) ]
 main_test: Fail  # Dartium needs to check for both main() and main(args).
@@ skipping 39 matching lines @@
 shuffle_test: Fail # IE doesn't support typed data.
 
 [ $compiler == dart2js && $runtime == chromeOnAndroid ]
 list_as_map_test: Pass, Slow # TODO(kasperl): Please triage.
 
 [ $compiler == dart2js && ($runtime == firefox || $runtime == safari || $runtime == chrome || $runtime == drt) ]
 
 [ $compiler == dart2js && ($runtime == d8 || $runtime == chrome || $runtime == drt || $runtime == safari) ]
 string_trimlr_test/none: Fail # Bug in v8. Fixed in v8 r19222, 2014-02-10.
 
+[ $compiler == dart2js && ($runtime == d8 || $runtime == drt) ]
+string_case_test/02: Fail, OK  # Bug in our version of V8.
+
+[ $compiler == dart2js && ($runtime == ie9 || $runtime == ie10) ]
+string_case_test/01: Fail, OK  # Bug in IE.
+string_case_test/02: Fail, OK  # Bug in IE.
+
+[ $compiler == dart2js && ($runtime == ff || $runtime == jsshell) ]
+string_case_test/01: Fail, OK  # Bug in Firefox.
+
+[ $compiler == dart2js && $runtime == dartium ]
+string_case_test/02: Fail, OK  # Bug in dartium version of V8.
+string_case_test/03: Fail, OK  # Bug in dartium version of V8.
+
+
 [ $compiler == dart2js && $checked ]
 map_test: Crash # Issue 17829
 
 [ $compiler == dart2dart ]
 compare_to2_test: Fail # inherited from VM
 unicode_test: Fail # inherited from VM
 
 [ $compiler == dart2dart && $minified ]
 error_stack_trace1_test: Fail # Fails in minified mode, test depends on method names.
 
@@ skipping 27 matching lines @@
 iterable_element_at_test: StaticWarning, OK # Test generates errors on purpose.
 num_clamp_test: StaticWarning, OK # Test generates errors on purpose.
 string_test: StaticWarning, OK # Test generates error on purpose.
 
 [ $compiler == dart2js && $runtime == safari ]
 list_test/01: Fail # Safari bug: Array(-2) seen as dead code.
 
 [ $runtime == ie9 || $runtime == ie10 ]
 num_parse_test: RuntimeError  # Issue 15316
 num_parse_test/01: RuntimeError  # Issue 15316