Error on attempt to link amd64 with binutils 2.17.50 linker

[emaste]

Summary

We still need some binutils components so cannot include BINUTILS_BOOTSTRAP in BROKEN_OPTIONS. Add an explicit error rather than building a broken kernel.

[emaste]

Makefile.inc1

2094 ↗

(On Diff #42364)

I could add && make(buildkernel), but I think it's reasonable to just disallow it; userland ifunc use will come too.

[kib]

IMO it is more useful to check the ${LD} features, or at least the ${LD} version.

[imp]

In D15378#324222, @kib wrote:

IMO it is more useful to check the ${LD} features, or at least the ${LD} version.

I agree. ifuncs is but the first thing... It would be good to know the features needed so that latter-day binutils can be used, but also flagged if we have a new one of these.

[emaste]

I don't think ${LINKER_FEATURES} here is right, because it will be the host's linker at this point. Let me see...

[emaste]

Add ifunc linker feature and test for it in kern.pre.mk in the amd64 case.