Changes in highlighting

[jrnold]

• Highlight all functions as matched by a valid pattern before (.
• Highlight everything with a bounded range < ... > and make it stand out less than the surrounding text.

[kaz-yos]

This requires recognizing <...> as paired parentheses where appropriate.

I have written a pending spec, but have not implemented the feature, yet.

c++-mode supports this so adopting some code should do this, but it is scattered and I have not been able to figure out what to adopt. https://github.com/emacs-mirror/emacs/search?q=c-recognize-%3C%3E-arglists&unscoped_q=c-recognize-%3C%3E-arglists