ustreamer and ustreamer-dump import 64-bit atomics from libatomic where
the compiler cannot inline them, but the build links the library on
every architecture. ATOMIC64_DEPENDS restricts the dependency to the
targets that need it; --as-needed drops the unused library elsewhere.
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Daniel Golle
763e45c890