https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81253
--- Comment #4 from Philipp <kidon at posteo dot de> ---
I use the official FreeBSD port for building GCC 6:
http://www.freshports.org/lang/gcc6
The dependencies are resolved automatically. I did not recompile them with
altered flags (all libraries are build without additional CFLAGS).
The following options have been used for building GCC 6:
BOOTSTRAP=on (Build using a full bootstrap)
GRAPHITE=off (Support for Graphite loop optimizations)
JAVA=off (Java platform support)
The libraries are linked dynamically.