The DFSClient and DataNode should use the shared memory segments and unified cache added in the other HDFS-5182 subtasks to communicate short-circuit information.
TestBlockReaderLocal fails if native code is not loaded or platform is Windows.
HDFS cannot run on Windows since short-circuit shared memory segment changes.
TestBlockReaderLocal fails if native library is not available
fix DFSClient issue without libhadoop.so and some other ShortCircuitShm cleanups