8276348: Use blessed modifier order in java.base

Reviewed-by: dfuchs, darcy, iris, rriggs, martin

src/java.base/share/classes/sun/nio/ch/FileChannelImpl.java

@@ -888,7 +888,7 @@ public class FileChannelImpl
 
     // -- Memory-mapped buffers --
 
-    private static abstract class Unmapper
+    private abstract static class Unmapper
         implements Runnable, UnmapperProxy
     {
         // may be required to close file