Testing with --target=FOO

[matthew green]

actually, one thing that has annoyed me for a while (infact, ever
since i first realised it was the case) is that all the CPU
components are thrown into the one shared object.   i've often
been annoyed because my newly installed libcgencpu.la, built for
a only the cpu i'm working on, suddenly can't run other cpu's.
also, a full libcgencpu.so can get REALLY large.

so, back to ben's question, i'd prefer it if all cpus were built
always (possibly some configury to disable them?), but that they
each had their own component library.  that should fix the testing
problem ben has raised, as well as my issues above.


.mrg.