bpo-34080: Fix a memory leak in the compiler. (GH-8222)

(cherry picked from commit 993030aa)
Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

Misc/NEWS.d/next/Core and Builtins/2018-07-10-11-24-16.bpo-34080.8t7PtO.rst

+Fixed a memory leak in the compiler when it raised some uncommon errors
+during tokenizing.

Python/pythonrun.c

@@ -1590,7 +1590,7 @@ err_input(perrdetail *err)
     errtype = PyExc_SyntaxError;
     switch (err->error) {
     case E_ERROR:
-        return;
+        goto cleanup;
     case E_SYNTAX:
         errtype = PyExc_IndentationError;
         if (err->expected == INDENT)