chore: Utilize LazyLock instead of OnceLock for fft calculations

Author: SuchAFuriousDeath

core/src/avm2/globals/flash/media/sound_mixer.rs

@@ -6,7 +6,10 @@ use crate::avm2::value::Value;
 use crate::avm2::Error;
 use crate::avm2_stub_getter;
 use crate::display_object::SoundTransform;
-use std::sync::{Arc, OnceLock};
+use std::{
+    ops::Deref,
+    sync::{Arc, LazyLock},
+};
 
 /// Implements `soundTransform`'s getter
 ///
@@ -107,11 +110,11 @@ pub fn compute_spectrum<'gc>(
     };
 
     if fft {
-        // TODO: Use `std::sync::LazyLock` once it's stabilized?
-        static FFT: OnceLock<Arc<dyn realfft::RealToComplex<f32>>> = OnceLock::new();
+        static FFT: LazyLock<Arc<dyn realfft::RealToComplex<f32>>> =
+            LazyLock::new(|| realfft::RealFftPlanner::new().plan_fft_forward(2048));
 
         // Flash Player appears to do a 2048-long FFT with only the first 512 samples filled in...
-        let fft = FFT.get_or_init(|| realfft::RealFftPlanner::new().plan_fft_forward(2048));
+        let fft = FFT.deref();
 
         let mut in_left = fft.make_input_vec();
         let mut in_right = fft.make_input_vec();