Fix missing bidi for extension.

src/bidi.js

@@ -3,7 +3,7 @@
 
 'use strict';
 
-var bidi = (function bidiClosure() {
+var bidi = PDFJS.bidi = (function bidiClosure() {
   // Character types for symbols from 0000 to 00FF.
   var baseTypes = [
     'BN', 'BN', 'BN', 'BN', 'BN', 'BN', 'BN', 'BN', 'BN', 'S', 'B', 'S', 'WS',

web/viewer.js

@@ -1097,7 +1097,7 @@ var TextLayerBuilder = function textLayerBuilder(textLayerDiv) {
     textDiv.style.fontSize = fontHeight + 'px';
     textDiv.style.left = text.geom.x + 'px';
     textDiv.style.top = (text.geom.y - fontHeight) + 'px';
-    textDiv.textContent = bidi(text, -1);
+    textDiv.textContent = PDFJS.bidi(text, -1);
     textDiv.dir = text.direction;
     textDiv.dataset.textLength = text.length;
     this.textDivs.push(textDiv);