debuilding gcc-3.3 and doxygen

[csj <csj@zapo.net>]

Am I the only one who can't build gcc-3.3 (3.3.3ds5-1)?  The
build appears to succeed until the point where the documentation
is being built.

Tail of gcc-3.3_3.3.3ds5-1_i386.build:

To avoid this warning please update your configuration file using "doxygen -u"
Warning: Tag `EXT_DOC_PATHS' at line 1074 of file /xb/build/debuild/newbuild/gcc-3.3-3.3.3ds5/build/i486-linux/libstdc++-v3/docs/doxygen/user.cfg has become obsolete.
To avoid this warning please update your configuration file using "doxygen -u"

From then there's hours of high CPU activity until I abort the
build.  I see a doxygen *++-related bug, but so far the version of
doxygen in unstable is still the same as the one in testing.