Unsafe.{get,put}-X-Unaligned; Efficient array comparison intrinsics

[Andrew Haley]

John's suggestion works well; the code is smaller and neater.

http://cr.openjdk.java.net/~aph/unaligned.jdk.3/
http://cr.openjdk.java.net/~aph/unaligned.hotspot.3/hotspot.patch

Andrew.