Clip OOB values in call data load and copy (#448)

The OOB logic is implemented in the runtime but truncation circumvented
it.

Closes #263

---------

Signed-off-by: xermicus <cyrill@parity.io>
Signed-off-by: Cyrill Leutwiler <bigcyrill@hotmail.com>

crates/integration/codesize.json

@@ -1,10 +1,10 @@
 {
-  "Baseline": 911,
-  "Computation": 2337,
-  "DivisionArithmetics": 14488,
-  "ERC20": 17189,
-  "Events": 1672,
-  "FibonacciIterative": 1454,
-  "Flipper": 2106,
-  "SHA1": 7814
+  "Baseline": 864,
+  "Computation": 2323,
+  "DivisionArithmetics": 14475,
+  "ERC20": 17229,
+  "Events": 1663,
+  "FibonacciIterative": 1421,
+  "Flipper": 2154,
+  "SHA1": 7751
 }

crates/integration/contracts/MemoryBounds.sol

@@ -21,12 +21,43 @@ pragma solidity ^0.8.24;
           "Instantiated": 0
         }
       }
+    },
+    {
+      "Call": {
+        "dest": {
+          "Instantiated": 0
+        },
+        "data": "489eb33e00000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000001a300000000000000000000000000000000000000000000000000000000000000"
+      }
+    },
+    {
+      "Call": {
+        "dest": {
+          "Instantiated": 0
+        },
+        "data": "db1ff7bb00000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000001a300000000000000000000000000000000000000000000000000000000000000"
+      }
     }
   ]
 }
 */
 
 contract MemoryBounds {
+    function oobLoad(bytes memory data) public pure returns (uint256, bytes memory) {
+        uint256 result1;
+        assembly {
+            let ptr := mload(add(data, 0x20))
+            result1 := calldataload(ptr)
+        }
+        return (result1, data);
+    }
+
+    function oobCopy(bytes memory data) public pure returns (uint256, bytes memory) {
+        assembly {
+            calldatacopy(0, 0x3a0000000000000000000000000000000000, 0x20)
+        }
+    }
+
     fallback() external {
         assembly {
             // Accessing OOB offsets should always work when the length is 0.