Add workaround for bug 9382, which introduced by fixing bug 5933

This change is required to fix following compiler issues:
- [Issue 5933](http://d.puremagic.com/issues/show_bug.cgi?id=5933) - Cannot retrieve the return type of an auto-return member function
- [Issue 7159](http://d.puremagic.com/issues/show_bug.cgi?id=7159) - Forward reference when casting auto return method
- [Issue 9377](http://d.puremagic.com/issues/show_bug.cgi?id=9377) - Link-failure regression cause by fixing issue 8504

In current, `std.numeric` module has an issue described in [bugzilla 9382](http://d.puremagic.com/issues/show_bug.cgi?id=9382). This change avoids such a "recursive alias declaration" error after compiler issues fixed.