Hi, as almost expected r233572 needs to be back-ported to gcc-5 and gcc-4.9 branches in order to be built by gcc-6. It applies cleanly to both branches. But unfortunately PR 69881 prevents boot-strapping gcc-4.9 in the moment. Boot-strap and regression-test of gcc-5 on x86_64-pc-linux-gnu. OK for gcc-5 and gcc-4.9 when PR 69881 is resolved? Thanks Bernd.