许多文章都宣称可以在官网下载到ARM64的Firefox,其实不然
https://blog.mozilla.org/futurereleases/2019/04/11/firefox-beta-for-windows-10-on-qualcomm-snapdragon-always-connected-pcs-now-available/
https://www.xda-developers.com/mozilla-firefox-windows-10-arm64-snapdragon/
但实际上官网没这个选项
解决方案参见:https://support.mozilla.org/zh-CN/questions/1264477