Network_test: Conform it with functional access changes in Ruby

Addition of functional access support to Ruby necessitated some changes to
the way coherence protocols are written. I had forgotten to update the
Network_test protocol. This patch makes those updates.

src/mem/protocol/Network_test-cache.sm

@@ -131,6 +131,9 @@ machine(L1Cache, "Network_test L1 Cache")
     return OOD;
   }
 
+  DataBlock getDataBlock(Address addr), return_by_ref="yes" {
+    error("Network Test does not support get data block.");
+  }
 
   // NETWORK PORTS
 

src/mem/protocol/Network_test-dir.sm

@@ -55,7 +55,7 @@ machine(Directory, "Network_test Directory")
 
   // TYPES
   // DirectoryEntry
-  structure(Entry, desc="...") {
+  structure(Entry, desc="...", interface="AbstractEntry") {
     State DirectoryState,          desc="Directory state";
     DataBlock DataBlk,             desc="data for the block";
   }
@@ -76,6 +76,10 @@ machine(Directory, "Network_test Directory")
   void setAccessPermission(Address addr, State state) {
   }
 
+  DataBlock getDataBlock(Address addr), return_by_ref="yes" {
+    error("Network Test does not support get data block.");
+  }
+
   // ** IN_PORTS **
 
   in_port(requestQueue_in, RequestMsg, requestToDir) {