NetworkPkg: Source fixes and cleanup for ARMGCC compiles

- Fix EFI_IPv4_ADDRESS usages to use a macro to copy the structure
   instead of direct assignment, to avoid runtime alignment errors.
- Delete excess local variables that are initialized but otherwise unused.
- Add LibraryClasses.ARM & AARCH64 section in NetworkPkg.dsc file,
   containing a CompilerIntrinsicsLib null-library, required for successful
  standalone package builds (copied from MdeModulePkg.dsc).

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Randy Pawell <randy_pawell@hp.com>
Reviewed-by: Fu Siyuan <siyuan.fu@intel.com>
Reviewed-by: Ye Ting <ting.ye@intel.com>


git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16472 6f19259b-4bc3-4df7-8a09-765794883524

NetworkPkg/Ip6Dxe/Ip6Impl.c

@@ -1,6 +1,7 @@
 /** @file
   Implementation of EFI_IP6_PROTOCOL protocol interfaces.
 
+  (C) Copyright 2014 Hewlett-Packard Development Company, L.P.<BR>
   Copyright (c) 2009 - 2014, Intel Corporation. All rights reserved.<BR>
 
   This program and the accompanying materials
@@ -1761,7 +1762,6 @@ EfiIp6Cancel (
   )
 {
   IP6_PROTOCOL              *IpInstance;
-  IP6_SERVICE               *IpSb;
   EFI_STATUS                Status;
   EFI_TPL                   OldTpl;
 
@@ -1770,7 +1770,6 @@ EfiIp6Cancel (
   }
 
   IpInstance = IP6_INSTANCE_FROM_PROTOCOL (This);
-  IpSb       = IpInstance->Service;
 
   OldTpl = gBS->RaiseTPL (TPL_CALLBACK);