optimize: avoid generating drop glue for StepResult

fix-vm/src/instructions/arithmetic.rs

@@ -32,7 +32,7 @@ impl<'gc> crate::Vm<'gc> {
                 self.push_stack(val);
                 StepResult::Continue
             }
-            Err(e) => e.into_step_result(),
+            Err(e) => self.finish_vm_err(e),
         }
     }
 
@@ -76,7 +76,7 @@ impl<'gc> crate::Vm<'gc> {
                 self.push_stack(val);
                 StepResult::Continue
             }
-            Err(e) => e.into_step_result(),
+            Err(e) => self.finish_vm_err(e),
         }
     }
 
@@ -96,10 +96,9 @@ impl<'gc> crate::Vm<'gc> {
         let lhs = self.pop_stack_forced();
         match (get_num(rhs), get_num(lhs)) {
             (_, Some(NixNum::Int(0))) | (_, Some(NixNum::Float(0.))) => {
-                return VmError::Uncatchable(fix_error::Error::eval_error(
+                return self.finish_vm_err(VmError::Uncatchable(fix_error::Error::eval_error(
                     "division by zero",
-                ))
-                .into_step_result();
+                )));
             }
             _ => {}
         }
@@ -109,7 +108,7 @@ impl<'gc> crate::Vm<'gc> {
                 self.push_stack(val);
                 StepResult::Continue
             }
-            Err(e) => e.into_step_result(),
+            Err(e) => self.finish_vm_err(e),
         }
     }
 
@@ -128,7 +127,7 @@ impl<'gc> crate::Vm<'gc> {
         }
         let eq = match self.values_equal(ctx) {
             Ok(eq) => eq,
-            Err(e) => return e.into_step_result(),
+            Err(e) => return self.finish_vm_err(e),
         };
         self.push_stack(Value::new_inline(eq));
         StepResult::Continue
@@ -149,7 +148,7 @@ impl<'gc> crate::Vm<'gc> {
         }
         let eq = match self.values_equal(ctx) {
             Ok(eq) => eq,
-            Err(e) => return e.into_step_result(),
+            Err(e) => return self.finish_vm_err(e),
         };
         self.push_stack(Value::new_inline(!eq));
         StepResult::Continue
@@ -210,7 +209,7 @@ impl<'gc> crate::Vm<'gc> {
         }
         match self.compare_values_inner(ctx, pred) {
             Ok(()) => StepResult::Continue,
-            Err(e) => e.into_step_result(),
+            Err(e) => self.finish_vm_err(e),
         }
     }
 
@@ -229,16 +228,14 @@ impl<'gc> crate::Vm<'gc> {
         let rhs = self.pop_stack_forced();
         let lhs = self.pop_stack_forced();
         let Some(l) = lhs.as_gc::<crate::List>() else {
-            return VmError::Uncatchable(fix_error::Error::eval_error(
+            return self.finish_err(fix_error::Error::eval_error(
                 "cannot concatenate: left operand is not a list",
-            ))
-            .into_step_result();
+            ));
         };
         let Some(r) = rhs.as_gc::<crate::List>() else {
-            return VmError::Uncatchable(fix_error::Error::eval_error(
+            return self.finish_err(fix_error::Error::eval_error(
                 "cannot concatenate: right operand is not a list",
-            ))
-            .into_step_result();
+            ));
         };
         let mut items = smallvec::SmallVec::new();
         items.extend_from_slice(&l);
@@ -262,16 +259,14 @@ impl<'gc> crate::Vm<'gc> {
         let rhs = self.pop_stack_forced();
         let lhs = self.pop_stack_forced();
         let Some(l) = lhs.as_gc::<crate::AttrSet>() else {
-            return VmError::Uncatchable(fix_error::Error::eval_error(
+            return self.finish_err(fix_error::Error::eval_error(
                 "cannot update: left operand is not a set",
-            ))
-            .into_step_result();
+            ));
         };
         let Some(r) = rhs.as_gc::<crate::AttrSet>() else {
-            return VmError::Uncatchable(fix_error::Error::eval_error(
+            return self.finish_err(fix_error::Error::eval_error(
                 "cannot update: right operand is not a set",
-            ))
-            .into_step_result();
+            ));
         };
         self.push_stack(Value::new_gc(l.merge(&r, mc)));
         StepResult::Continue