[Build System] Enable -fno-semantic-interposition

[diver]

This is from ​https://github.com/haikuports/haikuports/issues/4806

According to the ticket we could probably enable this for Haiku's kernel (and maybe app_server also) as well as libbe.so

[waddlesplash]

We already do this for the entire system: ​https://xref.landonf.org/source/xref/haiku/build/jam/ArchitectureRules#345

:)

[waddlesplash]

Ah, I guess we don't do it for the whole system, just for the kernel. Indeed, probably we could do it for everything but libroot.so, I suppose? Or maybe more broadly still?

[korli]

"for the kernel": it only makes sense for kernel add-ons, right?

[waddlesplash]

No, it makes sense for the kernel itself, too, because kernel addons do not override symbols for the kernel, only for themselves.

While libroot POSIX functions need to allow interposition, I don't think libbe ones do (indeed it mostly doesn't make sense to do that.) So we may be able to turn it on there.