Fix VM memory allocation optimizations by reducing what we allocate on the heap

internal/object/array.go

@@ -25,7 +25,7 @@ func (ao *Array) PopLeft() Object {
 		ao.Elements = ao.Elements[1:]
 		return e
 	}
-	return &Null{}
+	return Null{}
 }
 
 func (ao *Array) PopRight() Object {
@@ -34,7 +34,7 @@ func (ao *Array) PopRight() Object {
 		ao.Elements = ao.Elements[:(len(ao.Elements) - 1)]
 		return e
 	}
-	return &Null{}
+	return Null{}
 }
 
 func (ao *Array) Prepend(obj Object) {
@@ -89,7 +89,7 @@ func (ao *Array) Mul(other Object) (Object, error) {
 	}
 
 	var elements []Object
-	N := int(other.(*Integer).Value)
+	N := int(other.(Integer).Value)
 	for i := 0; i < N; i++ {
 		elements = append(elements, ao.Elements...)
 	}
@@ -102,10 +102,10 @@ func (ao *Array) Get(index Object) (Object, error) {
 		return nil, fmt.Errorf("invalid type for array index, expected Integer got %s", index.Type())
 	}
 
-	i := index.(*Integer).Value
+	i := index.(Integer).Value
 	N := int64(len(ao.Elements))
 	if i < 0 || i >= N {
-		return &Null{}, nil
+		return Null{}, nil
 	}
 
 	return ao.Elements[i], nil
@@ -116,7 +116,7 @@ func (ao *Array) Set(index, other Object) error {
 		return fmt.Errorf("invalid type for array index, expected Integer got %s", index.Type())
 	}
 
-	i := index.(*Integer).Value
+	i := index.(Integer).Value
 	N := int64(len(ao.Elements))
 	if i < 0 || i >= N {
 		return fmt.Errorf("index out of bounds %d with array length %d", i, N)