fix(JS: BitSet): Export the BitSet class as it is now used in the ErrorListener (#4746)

Signed-off-by: hutcheb <[email protected]>

Author: hutcheb

runtime/JavaScript/src/antlr4/misc/index.d.ts

@@ -1,3 +1,4 @@
+export * from './BitSet'
 export * from './Interval'
 export * from './IntervalSet';
 

runtime/JavaScript/src/antlr4/misc/index.js

@@ -1,4 +1,5 @@
+import BitSet from './BitSet.js';
 import Interval from './Interval.js';
 import IntervalSet from './IntervalSet.js';
 
-export default { Interval, IntervalSet }
+export default { BitSet, Interval, IntervalSet }