RFR: JDK-8067292 - Hangs when read in UARTEvent.INPUT_DATA_AVAILABLE callback in JavaME

[alexey mironov]

issue: https://bugs.openjdk.java.net/browse/JDK-8067292
webrev: http://cr.openjdk.java.net/~amironov/8067292/

Please review the changes made in order to add code that fix problem 
with hangs in JavaME.

Regards,
Alexey