Bug 1531293 - Enable javascript.options.bigint on Nightly r=jandem

Differential Revision: https://phabricator.services.mozilla.com/D21528

--HG--
extra : moz-landing-system : lando

modules/libpref/init/all.js

@@ -1600,7 +1600,11 @@ pref("javascript.options.spectre.jit_to_C++_calls", true);
 pref("javascript.options.streams", true);
 
 // BigInt API
+#ifdef NIGHTLY_BUILD
+pref("javascript.options.bigint", true);
+#else
 pref("javascript.options.bigint", false);
+#endif
 
 // Dynamic module import.
 #ifdef NIGHTLY_BUILD