Teach the parsermodule about floor division.  Fixes

[ 676521 ] parser module validation failure

bugfix candidate.
diff --git a/Lib/test/test_parser.py b/Lib/test/test_parser.py
index c0b1bfc..81708b5 100644
--- a/Lib/test/test_parser.py
+++ b/Lib/test/test_parser.py
@@ -51,6 +51,10 @@
         self.check_expr("foo(a, b, c, *args, **kw)")
         self.check_expr("foo(a, b, c, **kw)")
         self.check_expr("foo + bar")
+        self.check_expr("foo - bar")
+        self.check_expr("foo * bar")
+        self.check_expr("foo / bar")
+        self.check_expr("foo // bar")
         self.check_expr("lambda: 0")
         self.check_expr("lambda x: 0")
         self.check_expr("lambda *y: 0")
@@ -85,6 +89,7 @@
         self.check_suite("a -= b")
         self.check_suite("a *= b")
         self.check_suite("a /= b")
+        self.check_suite("a //= b")
         self.check_suite("a %= b")
         self.check_suite("a &= b")
         self.check_suite("a |= b")