The NetBSD-current/i386 build is working again. The following commits were made between the last failed build and the successful build:
2019.05.11.17.21.07 kre src/usr.sbin/cpuctl/arch/i386.c,v 1.98 2019.05.11.17.44.16 christos src/external/mit/xorg/lib/gallium/Makefile,v 1.26 Log files can be found at: http://releng.NetBSD.org/b5reports/i386/commits-2019.05.html#2019.05.11.17.44.16