A test that checks if "tls.(*Conn)" appears in any symbol's name.
tls.Conn is a type, so the string "tls.(*Conn)" can only appear
in the name of a method of Conn. But the test code doesn't use
any of the methods. Not sure why this needs to be live. In
particular, the linker is now able to prune all methods of Conn.
Remove this requirement. In fact, just drop the only_conn test
case, as simply allocating a type doesn't necessarily bring
anything live.