Review request: 8055230: Rename attach provider implementation class

[Mandy Chung]

Webrev:
   http://cr.openjdk.java.net/~mchung/jdk9/webrevs/8055230/

This patch renames the class name of attach provider implementation class
to be the same for all platforms.  This simplifies the build logic and
removes the need for generating the service config file at build time.

The files renamed are
   unix/classes/sun/tools/attach/${OS}VirtualMachine.java
     -> ${OS}/classes/sun/tools/attach/VirtualMachineImpl.java
   unix/classes/sun/tools/attach/${OS}AttachProvider.java
     -> ${OS}/classes/sun/tools/attach/VirtualMachineImpl.java

   ${OS}/classes/sun/tools/attach/${OS}VirtualMachine.java
     -> ${OS}/classes/sun/tools/attach/VirtualMachineImpl.java
   ${OS}/classes/sun/tools/attach/${OS}AttachProvider.java
     -> ${OS}/classes/sun/tools/attach/VirtualMachineImpl.java

and also corresponding native files.

Mandy