[gentoo-user] Don't disable 'introspection'

[walt]

I don't understand 'introspection' enough to know why we need it, but
apparently we do, so don't use the -introspection useflag like I did.

The trouble I introduced a few weeks ago when I disabled introspection
was subtle enough that I didn't realize until yesterday that I even had
a problem.

Portage had been doing mildly insane things that other people were not
seeing, so as a test I removed the -introspection useflag and spent the
entire day rebuilding packages.  My portage problem appears to be
fixed.  I hope.

If anyone can splain what introspection does I'd be grateful.