Add Script data double escaped state errors.

Author: inikulin

lib/tokenizer/index.js

@@ -1195,11 +1195,15 @@ _[SCRIPT_DATA_DOUBLE_ESCAPED_STATE] = function scriptDataDoubleEscapedState(cp)
         this._emitChars('<');
     }
 
-    else if (cp === $.NULL)
+    else if (cp === $.NULL) {
+        this._err(ERR.unexpectedNullCharacter);
         this._emitChars(UNICODE.REPLACEMENT_CHARACTER);
+    }
 
-    else if (cp === $.EOF)
+    else if (cp === $.EOF) {
+        this._err(ERR.eofInScriptHtmlComment);
         this._emitEOFToken();
+    }
 
     else
         this._emitCodePoint(cp);