Remove dead ExpressionUnexpectedToken from parser-base.h

The method ExpressionUnexpectedToken is not referenced anywhere apart from its
definition. This CL removes it.

The association with the bug below is only through discovering the dead code
when working on a fix for that bug.

BUG=v8:5692

Review-Url: https://codereview.chromium.org/2688413009
Cr-Commit-Position: refs/heads/master@{#43203}

src/parsing/parser-base.h

@@ -1053,14 +1053,6 @@ class ParserBase {
     }
   }
 
-  void ExpressionUnexpectedToken() {
-    MessageTemplate::Template message = MessageTemplate::kUnexpectedToken;
-    const char* arg;
-    Scanner::Location location = scanner()->peek_location();
-    GetUnexpectedTokenMessage(peek(), &message, &location, &arg);
-    classifier()->RecordExpressionError(location, message, arg);
-  }
-
   void BindingPatternUnexpectedToken() {
     MessageTemplate::Template message = MessageTemplate::kUnexpectedToken;
     const char* arg;