Add several tests where the defined value of a macro is (or looks like) a macro
Many of these look quite similar to existing tests that are handled
correctly, yet none of these work. For example, in test 30 we have a
simple non-function macro "foo" that is defined as "bar(baz(success))"
and obviously non-function macro expansion has been working for a long
time. Similarly, if we had text of "bar(baz(success))" it would be
expanded correctly as well.
But when this otherwise functioning text appears as the body of a
macro, things don't work at all.
This is pointing out a fundamental problem with the current
approach. The current code does a recursive expansion of a macro
definition, but this doesn't involve the parsing machinery, so it
can't actually handle things like an arbitrary nesting of parentheses.
The fix will require the parser to stuff macro values back into the
lexer to get at all of the existing machinery when expanding macros.