RFR: 8143849: Integrate Marlin renderer per JEP 265

[Laurent Bourgès]

Please review this first patch to backport the Marlin renderer from jdk9.

JBS: https://bugs.openjdk.java.net/browse/JDK-8143849
webrev:
http://cr.openjdk.java.net/~lbourges/marlin8u/marlin-8.01/m01.8143849.patch
unshuffled patch:
http://cr.openjdk.java.net/~lbourges/marlin8u/marlin-8.01/unshuffled/

m01.8143849.patch + merge with marlin changes only from m01b.8149896.patch
(few lines), the bug 8149896 will not be backported later.

Changes:
- FloatMath.java: removed powerOfTwoD(int n) as done in m01b.8149896.patch

- MarlinCache.java & MarlinTileGenerator.java:
import jdk.internal.misc.Unsafe; => import sun.misc.Unsafe;

- MarlinUtils:
import jdk.internal.misc.JavaLangAccess; => import sun.misc.JavaLangAccess;
import jdk.internal.misc.SharedSecrets; => import sun.misc.SharedSecrets;

- OffHeapArray.java:
import sun.awt.util.ThreadGroupUtils; => import sun.misc.ThreadGroupUtils;
import jdk.internal.misc.Unsafe; => import sun.misc.Unsafe;

- Renderer.java:
import jdk.internal.misc.Unsafe; => import sun.misc.Unsafe;

1 Line change from m01b.8149896.patch:
private static final double POWER_2_TO_32 = FloatMath.powerOfTwoD(32); =>
private static final double POWER_2_TO_32 = 0x1.0p32;

- RenderingEngine.java:
I skipped any change to the RenderingEngine class to not change the default
renderer in jdk 8u.
FYI I moved those changes in the following file, not to be integrated:
http://cr.openjdk.java.net/~lbourges/marlin8u/marlin-8.01/m01.8143849-RenderingEngine.patch

- Add MarlinRenderingEngine in sun.java2d.pipe.RenderingEngine property
files

Best regards,
Laurent