Revert "methods are defined right after the module_eval, so we don't need to do"

This change breaks tests in activesupport/test/core_ext/module_test.rb:

* test_delegation_exception_backtrace
* test_delegation_exception_backtrace_with_allow_nil

This reverts commit 0167765e3f84260522bc2f32d926c1f5dd44957c.