mesa llvmpipe driver fails to build on ppc64el

While llvm is enabled on Debian and it builds fine, it fails on Ubuntu:

../../../../../src/gallium/drivers/llvmpipe/lp_setup_tri.c: In function ‘do_triangle_ccw’:
../../../../../src/gallium/drivers/llvmpipe/lp_setup_tri.c:723:1: internal compiler error: Segmentation fault
 }
 ^
Please submit a full bug report,
with preprocessed source if appropriate.

so it's a regression with gcc-5, debian uses gcc-4. I don't know if the build logs will be available "forever", but here's a link:

https://launchpadlibrarian.net/273788292/buildlog_ubuntu-yakkety-ppc64el.mesa_12.0.1-3ubuntu1_BUILDING.txt.gz

canonical-x ppa has another:
https://launchpadlibrarian.net/273723778/buildlog_ubuntu-yakkety-ppc64el.mesa_12.0.1-3ubuntu0.1_BUILDING.txt.gz