p2p: add CInv block message helper methods

src/protocol.h

@@ -419,11 +419,21 @@ public:
 
     // Single-message helper methods
     bool IsMsgTx() const { return type == MSG_TX; }
+    bool IsMsgBlk() const { return type == MSG_BLOCK; }
     bool IsMsgWtx() const { return type == MSG_WTX; }
-    bool IsMsgWitnessTx() const { return type == MSG_WITNESS_TX; }
+    bool IsMsgFilteredBlk() const { return type == MSG_FILTERED_BLOCK; }
+    bool IsMsgCmpctBlk() const { return type == MSG_CMPCT_BLOCK; }
+    bool IsMsgWitnessBlk() const { return type == MSG_WITNESS_BLOCK; }
 
     // Combined-message helper methods
-    bool IsGenTxMsg()     const { return type == MSG_TX || type == MSG_WTX || type == MSG_WITNESS_TX; }
+    bool IsGenTxMsg() const
+    {
+        return type == MSG_TX || type == MSG_WTX || type == MSG_WITNESS_TX;
+    }
+    bool IsGenBlkMsg() const
+    {
+        return type == MSG_BLOCK || type == MSG_FILTERED_BLOCK || type == MSG_CMPCT_BLOCK || type == MSG_WITNESS_BLOCK;
+    }
 
     int type;
     uint256 hash;