8275240: Change nested classes in jdk.attach to static nested classes

Reviewed-by: cjplummer, dholmes, sspitsyn

Author: turbanoff

src/jdk.attach/aix/classes/sun/tools/attach/VirtualMachineImpl.java

@@ -233,7 +233,7 @@ InputStream execute(String cmd, Object ... args) throws AgentLoadException, IOEx
     /*
      * InputStream for the socket connection to get target VM
      */
-    private class SocketInputStream extends InputStream {
+    private static class SocketInputStream extends InputStream {
         int s;
 
         public SocketInputStream(int s) {

src/jdk.attach/linux/classes/sun/tools/attach/VirtualMachineImpl.java

@@ -237,7 +237,7 @@ InputStream execute(String cmd, Object ... args) throws AgentLoadException, IOEx
     /*
      * InputStream for the socket connection to get target VM
      */
-    private class SocketInputStream extends InputStream {
+    private static class SocketInputStream extends InputStream {
         int s = -1;
 
         public SocketInputStream(int s) {

src/jdk.attach/macosx/classes/sun/tools/attach/VirtualMachineImpl.java

@@ -233,7 +233,7 @@ InputStream execute(String cmd, Object ... args) throws AgentLoadException, IOEx
     /*
      * InputStream for the socket connection to get target VM
      */
-    private class SocketInputStream extends InputStream {
+    private static class SocketInputStream extends InputStream {
         int s;
 
         public SocketInputStream(int s) {

src/jdk.attach/windows/classes/sun/tools/attach/VirtualMachineImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2021, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -29,8 +29,6 @@
 import com.sun.tools.attach.AttachNotSupportedException;
 import com.sun.tools.attach.spi.AttachProvider;
 
-import sun.tools.attach.HotSpotVirtualMachine;
-
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Random;
@@ -141,7 +139,7 @@ InputStream execute(String cmd, Object ... args)
     }
 
     // An InputStream based on a pipe to the target VM
-    private class PipedInputStream extends InputStream {
+    private static class PipedInputStream extends InputStream {
 
         private long hPipe;