[PSA] arm turbulence

[Mike Frysinger]

if you don't build for arm targets, then you can stop reading

some CLs have landed to have arm build by default with hardfp. that
means if you have existing arm build dirs, they are built with softfp,
and trying to mix the two won't work. so if you see errors like:
foo.o uses VFP register arguments, libxxx.so does not

you've done been bit. your only option is to delete your board dir
and start one fresh:
rm -rf /build/arm-generic
./setup_board --board=arm-generic

we haven't landed an upgrade hook to do this automatically as we have
another arm breakage in the pipe: changing ldso path. we hoped to
land all of these together to minimize breakage over time, but alas,
that seems to not have been the case.

there will be follow up information once things have finished shaking
out. g'luck, and god speed.
-mike