The NetBSD-current/i386 build is working again. The following commits were made between the last failed build and the successful build:
2018.05.23.07.06.45 wiz src/share/man/man7/signal.7,v 1.22 2018.05.23.07.08.13 wiz src/share/man/man7/audio.7,v 1.4 2018.05.23.07.24.37 maxv src/sys/arch/x86/include/cpu_extended_state.h,v 1.16 2018.05.23.07.24.37 maxv src/sys/arch/x86/include/specialreg.h,v 1.125 2018.05.23.07.33.55 para src/distrib/sets/lists/comp/mi,v 1.2195 2018.05.23.07.34.40 maxv src/sys/arch/x86/x86/fpu.c,v 1.29 2018.05.23.07.45.35 maxv src/sys/arch/amd64/conf/files.amd64,v 1.104 2018.05.23.07.45.35 maxv src/sys/arch/i386/conf/files.i386,v 1.394 2018.05.23.07.45.35 maxv src/sys/arch/x86/include/fpu.h,v 1.8 2018.05.23.07.45.35 maxv src/sys/arch/x86/x86/Attic/convert_xmm_s87.c,v 1.4 2018.05.23.07.45.35 maxv src/sys/arch/x86/x86/fpu.c,v 1.30 2018.05.23.07.45.35 maxv src/sys/arch/xen/conf/files.xen,v 1.169 Log files can be found at: http://releng.NetBSD.org/b5reports/i386/commits-2018.05.html#2018.05.23.07.45.35