Add missing import

llvm-svn: 299739

compiler-rt/unittests/lit.common.unit.cfg

@@ -39,6 +39,7 @@ if config.host_os == 'Darwin':
   # only works for code if it is stored at the top level of some module.
   # Therefore, we have to put the code in a .py file, add it to path, and import
   # it to store it in the config.
+  import site
   site.addsitedir(os.path.dirname(__file__))
   import lit_unittest_cfg_utils
   config.darwin_sanitizer_parallelism_group_func = \