Adding two tests to lock-in some resolution behavior. [ok'd by sung via chat]

These tests verify that shadowing a function (foo) within another function (bar)
affects all calls to foo within bar and not just those after the second
definition of foo.  I added a test for the pure function case and a test for the
member function case.



git-svn-id: http://svn.code.sf.net/p/chapel/code/trunk@23684 3a8e244f-b0f2-452b-bcba-4c88e055c3ca