8207146: Rename jdk.internal.misc.Unsafe::xxxObject to xxxReference

Reviewed-by: dholmes, thartmann

src/java.base/share/classes/java/math/BigDecimal.java

@@ -4079,7 +4079,7 @@ public class BigDecimal extends Number implements Comparable<BigDecimal> {
         }
 
         static void setIntValVolatile(BigDecimal bd, BigInteger val) {
-            unsafe.putObjectVolatile(bd, intValOffset, val);
+            unsafe.putReferenceVolatile(bd, intValOffset, val);
         }
     }
 

src/java.base/share/classes/java/math/BigInteger.java

@@ -4600,7 +4600,7 @@ public class BigInteger extends Number implements Comparable<BigInteger> {
         }
 
         static void putMag(BigInteger bi, int[] magnitude) {
-            unsafe.putObject(bi, magOffset, magnitude);
+            unsafe.putReference(bi, magOffset, magnitude);
         }
     }