[lldb][test] Re-enable TestDataFormatterLibcxxStringSimulator.py

Author: Michael137

lldb/test/API/functionalities/data-formatter/data-formatter-stl/libcxx-simulators/string/TestDataFormatterLibcxxStringSimulator.py

@@ -13,9 +13,6 @@
 class LibcxxStringDataFormatterSimulatorTestCase(TestBase):
     NO_DEBUG_INFO_TESTCASE = True
 
-    @skipIfDarwin
-    @skipIfWindows
-    @skipIfLinux
     def _run_test(self, defines):
         cxxflags_extras = " ".join(["-D%s" % d for d in defines])
         self.build(dictionary=dict(CXXFLAGS_EXTRAS=cxxflags_extras))