* configure.target: Use cpu_include_dir="config/cpu/sparc" for all
sparc targets.
* config/cpu/sparc/bits/atomicity.h: New file.
* config/cpu/sparc/sparc32/bits/atomicity.h: Removed.
* config/cpu/sparc/sparc64/bits/atomicity.h: Removed.
[[Split portion of a mixed commit.]]
From-SVN: r56897.2