bootstrap/30469 - Fix make profiledbootstrap

[Paolo Bonzini]

Daniel Jacobowitz wrote:
> This patch disables profiling flags for building libgcc.  I first tried
> disabling them in the top level makefile, but I think this is a better
> idea - there's no explicit reason we couldn't profile bootstrapped
> target libraries.  We just don't want to do _this_ one, which includes
> such things as crtbegin.o and libgcov.a.
> 
> OK?

Sure, it makes sense.

Paolo