Add test to exercise create2

Author: smoelius

integration/stylus/milestone_2.sol

@@ -62,6 +62,18 @@ contract C {
 
         greeter.greet();
     }
+
+    function test4() public payable {
+        print("address = {}".format(address(this)));
+
+        Greeter greeter0 = new Greeter{salt: 0}();
+        print("greeter0 = {}".format(address(greeter0)));
+        greeter0.greet();
+
+        Greeter greeter1 = new Greeter{salt: bytes32(uint256(1))}();
+        print("greeter1 = {}".format(address(greeter1)));
+        greeter1.greet();
+    }
 }
 
 contract Greeter {

src/emit/stylus/target.rs

@@ -12,6 +12,7 @@ use crate::emit::{expression::expression, ContractArgs, TargetRuntime, Variable}
 use crate::emit_context;
 use crate::sema::ast::{self, CallTy};
 use crate::sema::ast::{Function, Type};
+use ethers_core::utils::keccak256;
 use inkwell::types::{BasicTypeEnum, IntType};
 use inkwell::values::{
     ArrayValue, BasicMetadataValueEnum, BasicValue, BasicValueEnum, FunctionValue, IntValue,
@@ -684,6 +685,11 @@ impl<'a> TargetRuntime<'a> for StylusTarget {
 
         let code = super::cargo_stylus::contract_deployment_calldata(&code_without_metadata);
 
+        if std::env::var_os("DEBUG_CREATE2").is_some() {
+            let digest = keccak256(&code);
+            eprintln!("keccak256(initCode) = {}", hex::encode(digest));
+        }
+
         let code_ptr =
             bin.emit_global_string(&format!("binary_{}_code", created_contract.id), &code, true);
 

tests/stylus_tests/milestone_2.rs

@@ -40,6 +40,9 @@ fn milestone_2() {
 
     stdout = send(dir, &address, ["test3()", "--value=1000000000000000000"]).unwrap();
     println!("{}", stdout);
+
+    stdout = send(dir, &address, ["test4()", "--value=1000000000000000000"]).unwrap();
+    println!("{}", stdout);
 }
 
 fn label_test_output(stdout: &str) -> String {