From: Sam Ravnborg <sam@ravnborg.org>

In the i386 case we need to generate asm-offset.h, before starting building
the kernel tree.  Building asm-offset.h causes us to use one of the
shorthands in the top-level makefile, namely the one for .s files.  The one
that allows us to do: make some/dir/file.s

And this shorthand happens to have a dependency to scripts, therefore I did
not see this problem on i386.  But David hit it with sparc64, because there
is no asm-offset.h file.  No parallel stuff involved here, just an ordinary
error.