Fix unused parameters and variables

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@290459 91177308-0d34-0410-b5e6-96231b3b80d8

test/support/filesystem_test_helper.hpp

@@ -230,6 +230,7 @@ private:
         // check that the fs test root in the enviroment matches what we were
         // compiled with.
         static bool checked = checkDynamicTestRoot();
+        ((void)checked);
         std::string cmd = LIBCXX_FILESYSTEM_DYNAMIC_TEST_HELPER;
         cmd += " \"" + raw_cmd + "\"";
         int ret = std::system(cmd.c_str());