a5730cc510
80486 production was stopped by Intel on September 2007. Dropping the 486 configuration option from the GENERIC kernel improves performance slightly. Removing I486_CPU is consistent at this time: we don't support any processor without a FPU and the PC-98 arch, which frequently involved i486 CPUs, is also gone so we don't test such platforms anymore. Relnotes: yes MFC after: 2 weeks https://reviews.freebsd.org/D9879