add blockhash DOS attack test

test/libethereum/StateTestsFiller/stBlockHashTestFiller.json

@@ -122,5 +122,48 @@
             "secretKey" : "45a915e4d060149eb4365960e6a7a45f334393093061116b197e3240065ff2d8",
             "data" : ""
         }
+    },
+
+    "blockhashDOS-sec71" : {
+        "env" : {
+            "previousHash" : "5e20a0453cecd065ea59c37ac63e079ee08998b6045136a8ce6635c7912ec0b6",
+            "currentNumber" : "257",
+            "currentGasLimit" : "100000000",
+            "currentDifficulty" : "256",
+            "currentTimestamp" : 1,
+            "currentCoinbase" : "2adc25665018aa1fe0e6bc666dac8fc2697ff9ba"
+        },
+        "expect" : {
+            "095e7baea6a6c7c4c2dfeb977efac326af552d87" : {
+                "storage" : {
+                    "0x" : "0xc89efdaa54c0f20c7adf612882df0950f5a951637e0307cdcb4c672f298b8bc6",
+                    "0x01" : "0xad7c5bef027816a800da1736444fb58a807ef4c9603b7848673f7e3a68eb14a5",
+                    "0x02" : "0x6ca54da2c4784ea43fd88b3402de07ae4bced597cbb19f323b7595857a6720ae"
+                }
+            }
+        },
+        "pre" : {
+            "095e7baea6a6c7c4c2dfeb977efac326af552d87" : {
+                "balance" : "1000000000000000000",
+                "nonce" : "0",
+                "code" : "0x61010043035b804050600556",
+                "storage": {}
+            },
+            "a94f5374fce5edbc8e2a8697c15331677e6ebf0b" : {
+                "balance" : "1000000000",
+                "nonce" : "0",
+                "code" : "",
+                "storage": {}
+            }
+        },
+        "transaction" : {
+            "nonce" : "0",
+            "gasPrice" : "1",
+            "gasLimit" : "750000",
+            "to" : "095e7baea6a6c7c4c2dfeb977efac326af552d87",
+            "value" : "10",
+            "secretKey" : "45a915e4d060149eb4365960e6a7a45f334393093061116b197e3240065ff2d8",
+            "data" : ""
+        }
     }
 }