Log Message:
lang/gcc-aux: Update to gcc 4.6.4 (version 20130412)

This is a bug fix release, the final of the GCC 4.6 series.
The official change page is http://gcc.gnu.org/gcc-4.6/changes.html
According to it, 86 bugs have been resolved since version 4.6.3 was
released (2 P1 bugs, 20 P2 bugs).