PipedReader.java (ready): Throw IOException if pipe closed.

PipedReader.java (ready): Throw IOException if pipe closed.

	* java/io/PipedReader.java (ready): Throw IOException if pipe
	closed.
	* java/io/FilterReader.java (close): Don't clear `in'.
	* java/io/CharArrayReader.java (mark): Throw IOException if stream
	closed.
	(read, ready, reset, skip): Added exception message.
	* java/io/BufferedReader.java (mark, reset, ready, read, skip):
	Perform checkStatus check inside synchronized block.

From-SVN: r39641