Bug 1956589 - Fix Fuzzilli build on macOS r=jandem

Differential Revision: https://phabricator.services.mozilla.com/D243153

js/src/shell/js.cpp

@@ -4100,7 +4100,11 @@ static bool Fuzzilli(JSContext* cx, unsigned argc, Value* vp) {
         MOZ_ASSERT(false);
         break;
       case 3:
+      #if defined(JS_CODEGEN_X64) || defined(JS_CODEGEN_X86)
         __asm__("int3");
+      #elif defined(JS_CODEGEN_ARM64)
+        __asm__("brk #0");
+      #endif
         break;
       default:
         exit(1);

js/src/shell/moz.build

@@ -31,7 +31,7 @@ if CONFIG["FUZZING_INTERFACES"]:
     else:
         USE_LIBS += ["static:fuzzer-interface"]
 
-if CONFIG["FUZZING_JS_FUZZILLI"]:
+if CONFIG["FUZZING_JS_FUZZILLI"] and CONFIG["OS_ARCH"] == "Linux":
     OS_LIBS += ["rt"]
 
 DEFINES["EXPORT_JS_API"] = True