bug#22563: 25.0.90; etags missing support for attr_XXX and alias_method calls with parens

[Dmitry Gutov]

Now that we have support for paren-less calls (added in bug#22241), it
would be nice to support the same calls when parens are used, even
though they're vastly less popular in the context we're interested in.
If only for completeness.

We already support:

    attr_reader :foo, :bar, # comment
                :qux
    alias_method :foo, #cmmt
                 :bar

This would add support for:

    attr_reader(:foo, :bar, # comment
                :qux)
    alias_method(:foo, #cmmt
                 :bar)