overriding sfp-machine.h from an add-on

[Aldy Hernandez]

Hi folks!

I'm working on an add-on that needs to override
sysdeps/powerpc/soft-fp/sfp-machine.h.

I have:

  glibc-source/my-add-on/sysdeps/powerpc/soft-fp/sfp-machine.h

but the build system includes the add-on's soft-fp directory last:

-I../sysdeps/powerpc/soft-fp -I../my-add-on/sysdeps/powerpc/soft-fp

...hencing picking up the wrong sfp-machine.h.

I could put sfp-machine.h in my-add-on/sysdeps/powerpc/ which does get
included before, but that seems like cheating.

What's the recommended way of doing this?

Thanks.
Aldy