RFR [7011804] SequenceInputStream with lots of empty substreams can cause StackOverflowError

[Ivan Gerasimov]

Hello!

SequenceInputStream#read functions are implemented recursively.
This may cause stack overflow in some extreme cases with lots of empty 
substreams.

Would you please help review the fix?

BUGURL: https://bugs.openjdk.java.net/browse/7011804
WEBREV: http://cr.openjdk.java.net/~igerasim/7011804/0/webrev/

Sincerely yours,
Ivan