Add test invoking a macro with an argument containing (non-macro) parentheses.

Add test invoking a macro with an argument containing (non-macro) parentheses.

The macro invocation is defined to consume all text between a set of
matched parentheses. We previously tested for inner parentheses from a
nested function-like macro invocation. Here we test for inner
parentheses occuring on their own, (not part of another macro
invocation).