RFR 8143628: Fork sun.misc.Unsafe and jdk.internal.misc.Unsafe native method tables

[Mandy Chung]

> On Nov 26, 2015, at 1:55 AM, Paul Sandoz <paul.sandoz at oracle.com> wrote:
> 
> Hi,
> 
> This is a request for an optimistic review to fork the sun.misc.Unsafe and jdk.internal.misc.Unsafe native method tables so that we can evolve the latter e.g. for VarHandles unsafe work
> 
>  http://cr.openjdk.java.net/~psandoz/jdk9/JDK-8143628-unsafe-native-jdk/
>  http://cr.openjdk.java.net/~psandoz/jdk9/JDK-8143628-unsafe-native-hotspot/

Looks good.  About the tests, would it be better for these tests be placed in the jdk repo? 

Nit: extra lines in the testAccess method in several new tests can be removed. 

 144     static void testAccess(Object base, long offset) {
 145         // Plain
 146         {
 147             UNSAFE.putDouble(base, offset, 1.0d);
 148             double x = UNSAFE.getDouble(base, offset);
 149             assertEquals(x, 1.0d, "set double value");
 150         }
 151 
 152         // Volatile
 153         {
 154             UNSAFE.putDoubleVolatile(base, offset, 2.0d);
 155             double x = UNSAFE.getDoubleVolatile(base, offset);
 156             assertEquals(x, 2.0d, "putVolatile double value");
 157         }
 158 
 159 
 160 
 161 
 162     }