Enable SIMD for aarch64.

src/main.cpp

@@ -518,6 +518,14 @@ bool MainApp::OnInit()
 
 #endif // _WIN32 || __APPLE__
 
+#if __aarch64__
+    // For 64-bit ARM, it's safe to assume some form of SIMD is available,
+    // so make sure we enable it for soxr. (soxr will auto-enable on x86
+    // as appropriate, so no need to explicitly force on that platform).
+    wxSetEnv("SOXR_USE_SIMD32", "1");
+    wxSetEnv("SOXR_USE_SIMD64", "1");
+#endif // __aarch64__
+
 #if defined(UNOFFICIAL_RELEASE)
     // Terminate the application if the current date > expiration date
     wxDateTime buildDate;