avm1: Avoid allocation of some static strings

Prefer creating a static `AvmString` over allocating an owned one.

Author: relrelb

core/src/avm1/globals/bevel_filter.rs

@@ -373,13 +373,13 @@ pub fn set_blur_y<'gc>(
 }
 
 pub fn get_type<'gc>(
-    activation: &mut Activation<'_, 'gc, '_>,
+    _activation: &mut Activation<'_, 'gc, '_>,
     this: Object<'gc>,
     _args: &[Value<'gc>],
 ) -> Result<Value<'gc>, Error<'gc>> {
     if let Some(filter) = this.as_bevel_filter_object() {
         let type_: &WStr = filter.get_type().into();
-        return Ok(AvmString::new(activation.context.gc_context, type_).into());
+        return Ok(AvmString::from(type_).into());
     }
 
     Ok(Value::Undefined)

core/src/avm1/globals/displacement_map_filter.rs

@@ -219,13 +219,13 @@ pub fn set_map_point<'gc>(
 }
 
 pub fn mode<'gc>(
-    activation: &mut Activation<'_, 'gc, '_>,
+    _activation: &mut Activation<'_, 'gc, '_>,
     this: Object<'gc>,
     _args: &[Value<'gc>],
 ) -> Result<Value<'gc>, Error<'gc>> {
     if let Some(object) = this.as_displacement_map_filter_object() {
         let mode: &WStr = object.mode().into();
-        return Ok(AvmString::new(activation.context.gc_context, mode).into());
+        return Ok(AvmString::from(mode).into());
     }
 
     Ok(Value::Undefined)

core/src/avm1/globals/gradient_bevel_filter.rs

@@ -387,13 +387,13 @@ pub fn set_quality<'gc>(
 }
 
 pub fn get_type<'gc>(
-    activation: &mut Activation<'_, 'gc, '_>,
+    _activation: &mut Activation<'_, 'gc, '_>,
     this: Object<'gc>,
     _args: &[Value<'gc>],
 ) -> Result<Value<'gc>, Error<'gc>> {
     if let Some(filter) = this.as_gradient_bevel_filter_object() {
         let type_: &WStr = filter.get_type().into();
-        return Ok(AvmString::new(activation.context.gc_context, type_).into());
+        return Ok(AvmString::from(type_).into());
     }
 
     Ok(Value::Undefined)

core/src/avm1/globals/gradient_glow_filter.rs

@@ -387,13 +387,13 @@ pub fn set_quality<'gc>(
 }
 
 pub fn get_type<'gc>(
-    activation: &mut Activation<'_, 'gc, '_>,
+    _activation: &mut Activation<'_, 'gc, '_>,
     this: Object<'gc>,
     _args: &[Value<'gc>],
 ) -> Result<Value<'gc>, Error<'gc>> {
     if let Some(filter) = this.as_gradient_glow_filter_object() {
         let type_: &WStr = filter.get_type().into();
-        return Ok(AvmString::new(activation.context.gc_context, type_).into());
+        return Ok(AvmString::from(type_).into());
     }
 
     Ok(Value::Undefined)