Renamed dynasm backend to singlepass

lib/runtime-core/src/backend.rs

@@ -25,7 +25,7 @@ pub use crate::sig_registry::SigRegistry;
 #[derive(Serialize, Deserialize, Debug, Copy, Clone, PartialEq, Eq)]
 pub enum Backend {
     Cranelift,
-    Dynasm,
+    Singlepass,
     LLVM,
 }