[9] RFR(S): JDK-8039498: Add iterators to GrowableArray

[Tobias Hartmann]

Hi,

please review the following patch.

*Problem:*
The implementation of "JDK-8015774: Add support for multiple code heaps" 
needs to manage multiple code heaps in the code cache. They will be 
stored in a GrowableArray data structure. Frequent accesses to the array 
using indices make the code more unreadable and error prone and result 
in code duplication.
Bug: https://bugs.openjdk.java.net/browse/JDK-8039498

*Solution:*
To simplify the access to the code heaps, the GrowableArray is adapted 
to support STL-style iterators. Further, custom iterators allow to only 
iterate over elements that satisfy a given predicate. This helps to 
access only specific code heaps.
Webrev: http://cr.openjdk.java.net/~anoll/8039498/webrev.01/

*Tests:*
JPRT with segmented code cache implementation (to be reviewed)

Thanks,

Tobias