better type assertion ergonomic

fix-vm/src/dispatch_tailcall.rs

@@ -2,7 +2,7 @@
 
 use gc_arena::Mutation;
 
-use crate::{BytecodeReader, StepResult, Vm, VmContext};
+use crate::{BytecodeReader, Step, Vm, VmContext};
 
 pub(crate) enum TailResult {
     YieldFuel(u32),
@@ -36,8 +36,8 @@ extern "rust-preserve-none" fn op_illegal<'gc, C: VmContext>(
 macro_rules! tail_dispatch_after {
     ($result:expr, $new_pc:expr, $vm:ident, $mc:ident, $ctx:ident, $bc:ident, $table:ident, $fuel:ident) => {{
         match $result {
-            StepResult::Continue => {}
-            StepResult::Done => return TailResult::Done,
+            Step::Continue => {}
+            Step::Done => return TailResult::Done,
         }
         let new_pc: u32 = $new_pc;
         if $fuel == 0 {