Bug 1567902: Don't emit an if-statement with an elided assertion in self-hosted code. r=jandem

Because that breaks profiles where extra-warnings are set.

Differential Revision: https://phabricator.services.mozilla.com/D39195

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

js/src/builtin/intl/CommonFunctions.js

@@ -145,9 +145,14 @@ function getUnicodeExtensions(locale) {
     if (!callFunction(ts.nextToken, ts))    \
         return null;
 
+#ifdef DEBUG
 #define NEXT_TOKEN_OR_ASSERT(ts)            \
     if (!callFunction(ts.nextToken, ts))    \
         assert(false, "unexpected invalid subtag");
+#else
+#define NEXT_TOKEN_OR_ASSERT(ts)            \
+    callFunction(ts.nextToken, ts);
+#endif
 
 // Assigns the current subtag part transformed to lower-case to the target.
 #define SUBTAG_VAR_OR_RETURN_NULL(ts, target)                                   \