Saying goodbye to asm.js

Firefox 148 disables SpiderMonkey's asm.js optimizations by default, with full removal planned for a future release. asm.js, Mozilla's 2013 technology for running C/C++ code at near-native speed on the web, paved the way for WebAssembly. Since WebAssembly has now fully succeeded and asm.js usage has largely migrated, maintaining the separate asm.js path only adds maintenance burden and attack surface. Existing asm.js code continues to run via the regular JIT without breaking, but recompiling to WebAssembly is recommended for better performance and smaller binaries. The asm.js compiler OdinMonkey is being retired after 13 years, succeeded by the WebAssembly compilers BaldrMonkey and RabaldrMonkey.