RFR: 8285868: x86_64 intrinsics for floating point methods isNaN, isFinite, IsInfinite

[Srinivas Vamsi Parasa]

We develop optimized x86_64 intrinsics for the floating point class check methods isNaN(), isFinite() and IsInfinite() for Float and Double classes. JMH benchmarks show ~8x improvement for isNan(), ~3x improvement for isInfinite() and 15% gain for isFinite().

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Commit messages:
 - 8285868: x86_64 intrinsics for floating point methods isNaN, isFinite and isInfinite

Changes: https://git.openjdk.java.net/jdk/pull/8459/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8459&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8285868
  Stats: 750 lines in 20 files changed: 748 ins; 0 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8459.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8459/head:pull/8459

PR: https://git.openjdk.java.net/jdk/pull/8459