avm1: Use u16 for Property::attributes

core/src/avm1/globals/object.rs

@@ -267,10 +267,10 @@ pub fn as_set_prop_flags<'gc>(
         return Ok(Value::Undefined);
     };
 
-    let set_flags = args.get(2).unwrap_or(&0.into()).coerce_to_f64(activation)? as u8;
+    let set_flags = args.get(2).unwrap_or(&0.into()).coerce_to_f64(activation)? as u16;
     let set_attributes = Attribute::from_bits_truncate(set_flags);
 
-    let clear_flags = args.get(3).unwrap_or(&0.into()).coerce_to_f64(activation)? as u8;
+    let clear_flags = args.get(3).unwrap_or(&0.into()).coerce_to_f64(activation)? as u16;
     let clear_attributes = Attribute::from_bits_truncate(clear_flags);
 
     if set_attributes.bits() != set_flags || clear_attributes.bits() != clear_flags {

core/src/avm1/property.rs

@@ -10,10 +10,11 @@ bitflags! {
     /// The values are significant and should match the order used by `object::as_set_prop_flags`.
     #[derive(Collect)]
     #[collect(require_static)]
-    pub struct Attribute: u8 {
-        const DONT_ENUM   = 1 << 0;
-        const DONT_DELETE = 1 << 1;
-        const READ_ONLY   = 1 << 2;
+    pub struct Attribute: u16 {
+        const DONT_ENUM     = 1 << 0;
+        const DONT_DELETE   = 1 << 1;
+        const READ_ONLY     = 1 << 2;
+        const VERSION_MASK  = 0xf << 9;
     }
 }
 

core/src/avm1/property_decl.rs

@@ -27,7 +27,7 @@ pub struct Declaration {
     // This should be an `Attribute`, but because of `const` shenanigans
     // we need to store the raw flags.
     // See the comment in the `declare_properties!` macro.
-    pub attributes: u8,
+    pub attributes: u16,
 }
 
 /// All the possible types of a [`Declaration`].