Fix Issue 1320: LiveEdit: text differencer fails with out of memory on large files

src/liveedit-debugger.js

Index: src/liveedit-debugger.js
diff --git a/src/liveedit-debugger.js b/src/liveedit-debugger.js
index e05c53ce1841b35c1f3ca19264b857d154a689a3..291bd52f30a27566f434f39a9c4941db8b223358 100644
--- a/src/liveedit-debugger.js
+++ b/src/liveedit-debugger.js
@@ -988,7 +988,11 @@ Debug.LiveEdit = new function() {
   this.SetScriptSource = SetScriptSource;
 
   function CompareStrings(s1, s2) {
-    return %LiveEditCompareStrings(s1, s2);
+    try {
+      return %LiveEditCompareStrings(s1, s2);
+    } catch (e) {
+      throw new Failure("Failed to calculate text difference: " + String(e));
+    }
   }
 
   // Applies the change to the script.