RFR: JDK-8146568 NegativeArraySizeException in ArrayList.grow(int)

[Martin Buchholz]

Hi Stuart et al,
Please review my fix for this corner case bug, including more
importantly some performance improvements.

https://bugs.openjdk.java.net/browse/JDK-8146568
http://cr.openjdk.java.net/~martin/webrevs/openjdk9/ArrayList-grow/