RFR: 8283726: x86 intrinsics for compare method in Integer and Long

[Vamsi Parasa]

Implements x86 intrinsics for compare() method in java.lang.Integer and java.lang.Long.

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Commit messages:
 - add JMH benchmarks
 - 8283726: x86 intrinsics for compare method in Integer and Long

Changes: https://git.openjdk.java.net/jdk/pull/7975/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=7975&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8283726
  Stats: 430 lines in 13 files changed: 428 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7975.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7975/head:pull/7975

PR: https://git.openjdk.java.net/jdk/pull/7975