Request for review: 6896617: Optimize sun.nio.cs.ISO_8859_1$Encode.encodeArrayLoop() on x86

[Vladimir Kozlov]

http://cr.openjdk.java.net/~kvn/6896617_jdk/webrev
Move encoding loop into separate method for which VM will use intrinsic 
on x86. I want to get agreement on this jdk change before I submit VM part.

This gives +1.6% performance improvement on SPECjAppServer2004 on x86.
Note, even without intrinsic (on other platforms) JIT will produce 
better code for this loop.

Thanks,
Vladimir