compiler-rt: Do not compile arm/sync_fetch_and_* and arm/switch* on armv5.
compiler-rt: Do not compile arm/sync_fetch_and_* and arm/switch* on armv5.

Signed-off-by: Moritz Hoffmann <53ba0aa052d551db5cb133c62d34e71044d0deba@inf.ethz.ch>

kishoredbn/barrelfish,BarrelfishOS/barrelfish,kishoredbn/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,kishoredbn/barrelfish,BarrelfishOS/barrelfish,kishoredbn/barrelfish,kishoredbn/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,BarrelfishOS/barrelfish,kishoredbn/barrelfish