I've now backported the following two patches
[boehm-gc] Avoid unstructured procfs on Solaris
https://gcc.gnu.org/ml/gcc-patches/2015-08/msg01591.html
[build] Use __cxa_atexit on Solaris 12+
https://gcc.gnu.org/ml/gcc-patches/2015-08/msg01593.html
to the gcc 5 bra
Over the next couple of weeks, I'll be submitting a couple of patches to
support Solaris 12. Some of them will fix bootstrap failures, others
support features new in that release.
Most of the patches are strictly Solaris specific, with only a few
needing approval. I'd like to commit them to main
