[Bug bootstrap/46037] --enable-stage1-languages=c,lto --enable-languages=c,lto --with-build-config=bootstrap-lto fails on darwin

[Jan Hubicka]

> Target attributes must be implying optimisation attributes.  Bug depends also
> on --with-{arch,tune,fpmath} settings.  I'll try and reproduce it on
> x86_64-linux, it should be possible if I choose the right settings - will reply
> again later.

Well, we probably should just go ahead and implement streaming of optimizaion attribute.
But still I don't see how this implicatoin happens.

Honza