Potentially work around https://github.com/JuliaLang/julia/issues/9185
Potentially work around https://github.com/JuliaLang/julia/issues/9185

This might be a x87-vs-SSE problem, since setting march to i686 for building the deps
but JULIA_CPU_TARGET to pentium4 for JIT code appears to work properly.
Need to verify that this doesn't bring back any of the i686 issues on 32 bit linux though.
yuyichao/julia-buildbot,kshyatt/julia-buildbot,yuyichao/julia-buildbot,staticfloat/julia-buildbot,staticfloat/julia-buildbot,kshyatt/julia-buildbot