ethers-solc: add immutableReferences output selector

It is a property on the deployed bytecode object
on the compiler output. This is the precursor for
`forge inspect <contract-name> immutableReferences`.

ethers-solc/src/artifacts/output_selection.rs

@@ -427,6 +427,7 @@ pub enum DeployedBytecodeOutputSelection {
     SourceMap,
     LinkReferences,
     GeneratedSources,
+    ImmutableReferences,
 }
 
 impl Serialize for DeployedBytecodeOutputSelection {
@@ -465,6 +466,9 @@ impl fmt::Display for DeployedBytecodeOutputSelection {
             DeployedBytecodeOutputSelection::GeneratedSources => {
                 f.write_str("evm.deployedBytecode.generatedSources")
             }
+            DeployedBytecodeOutputSelection::ImmutableReferences => {
+                f.write_str("evm.deployedBytecode.immutableReferences")
+            }
         }
     }
 }
@@ -487,6 +491,9 @@ impl FromStr for DeployedBytecodeOutputSelection {
             "evm.deployedBytecode.generatedSources" => {
                 Ok(DeployedBytecodeOutputSelection::GeneratedSources)
             }
+            "evm.deployedBytecode.immutableReferences" => {
+                Ok(DeployedBytecodeOutputSelection::ImmutableReferences)
+            }
             s => Err(format!("Invalid deployedBytecode selection: {}", s)),
         }
     }
@@ -573,4 +580,12 @@ mod tests {
         let s = serde_json::to_string(&empty).unwrap();
         assert_eq!(s, r#"{"contract.sol":{"*":[]}}"#);
     }
+
+    #[test]
+    fn deployed_bytecode_from_str() {
+        assert_eq!(
+            DeployedBytecodeOutputSelection::from_str("evm.deployedBytecode.immutableReferences").unwrap(),
+            DeployedBytecodeOutputSelection::ImmutableReferences
+        )
+    }
 }