[RESEND PATCH] Makeconfig: Set pie-ccflag to -fPIE by default

[Florian Weimer]

* Wilco Dijkstra:

> Well if changing the default of fPIC is unacceptable in GCC, adding a
> new option should help LLVM too since it could imply more than
> -fno-semantic-interposition.  A key question is whether we could
> require that exported symbols are marked explicitly so that we only
> emit GOT and PLT indirections on such exported symbols.

-flto with a linker plugin already covers this.  I don't think we need
anything else.  Maybe an LTO mode that only deals with visibility, but
otherwise does little cross-TU optimization?

Thanks,
Florian