powerpc: Add atomic_testand_{set,clear}_{int,long}
Add machine-optimized implementations for the following: * atomic_testandset_int * atomic_testandclear_int * atomic_testandset_long * atomic_testandclear_long This fixes the build with ISA_206_ATOMICS enabled. Add the associated atomic_testandset_32, atomic_testandclear_32, so that ice(4) can potentially build.