Enable libcxx map test on FreeBSD again

The test used to trigger an assertion failure "Cannot get layout of
forward declarations!", but it no longer fails when built with
Clang 3.4.1 (system compiler) or 3.5 from SVN on FreeBSD.

llvm.org/pr17231

llvm-svn: 218196

lldb/test/functionalities/data-formatter/data-formatter-stl/libcxx/map/TestDataFormatterLibccMap.py

@@ -19,7 +19,6 @@ class LibcxxMapDataFormatterTestCase(TestBase):
         self.buildDsym()
         self.data_formatter_commands()
 
-    @skipIfFreeBSD # llvm.org/pr17231
     @skipIfLinux # No standard locations for libc++ on Linux, so skip for now 
     @dwarf_test
     def test_with_dwarf_and_run_command(self):