MemCmd: Add a command for invalidation requests to LSQ

This command will be sent from the memory system (Ruby) to the LSQ of
an O3 CPU so that the LSQ, if it needs to, invalidates the address in
the request packet.

src/mem/packet.cc

@@ -168,6 +168,9 @@ MemCmd::commandInfo[] =
     { SET2(IsRequest, IsPrint), InvalidCmd, "PrintReq" },
     /* Flush Request */
     { SET3(IsRequest, IsFlush, NeedsExclusive), InvalidCmd, "FlushReq" },
+    /* Invalidation Request */
+    { SET3(NeedsExclusive, IsInvalidate, IsRequest),
+      InvalidCmd, "InvalidationReq" },
 };
 
 bool

src/mem/packet.hh

@@ -108,6 +108,7 @@ class MemCmd
         // Fake simulator-only commands
         PrintReq,       // Print state matching address
         FlushReq,      //request for a cache flush
+        InvalidationReq,   // request for address to be invalidated from lsq
         NUM_MEM_CMDS
     };