Comment # 6 on bug 63 from Iain Buclaw

It is related.  The configure script for GCC seems to have a slightly odd logic
for which languages it should enable in the stage1 phase.  It seems silly to me
that lang_requires_boot_languages should even be considered in
--disable-bootstrap builds, but hey ho...

The fix Brad has been waiting for - I can give you back that time when we meet
at Dconf this year. :)

https://github.com/D-Programming-GDC/GDC/commit/10335c0c00b5b2d2a3c31eb7bf6c2ce7b5e7012b