The NetBSD-current/i386 build is working again. The following commits were made between the last failed build and the successful build:
2016.12.09.13.06.02 martin src/sys/dev/audio.c,v 1.271 2016.12.09.13.06.41 roy src/sys/kern/kern_module.c,v 1.118 2016.12.09.13.16.22 christos src/sys/dev/audiobell.c,v 1.10 2016.12.09.13.16.22 christos src/sys/dev/audiobellvar.h,v 1.8 2016.12.09.13.16.22 christos src/sys/dev/spkr_synth.c,v 1.4 2016.12.09.13.26.11 christos src/sys/dev/audiobell.c,v 1.11 2016.12.09.13.26.11 christos src/sys/dev/audiobellvar.h,v 1.9 2016.12.09.13.26.11 christos src/sys/dev/spkr_synth.c,v 1.5 2016.12.09.13.26.47 christos src/sys/arch/arm/iomd/vidcaudio.c,v 1.54 Log files can be found at: http://releng.NetBSD.org/b5reports/i386/commits-2016.12.html#2016.12.09.13.26.47