[libcc1] drop unused field from C++ lang_identifier

for  gcc/cp/ChangeLog

	* cp-tree.h (lang_identifier): Drop oracle_looked_up, unused.

From-SVN: r248580

gcc/cp/ChangeLog

+2017-05-29  Alexandre Oliva <aoliva@redhat.com>
+
+	* cp-tree.h (lang_identifier): Drop oracle_looked_up, unused.
+
 2017-05-29  Nathan Sidwell  <nathan@acm.org>
 
 	PR c++/80891 (#1,#5)

gcc/cp/cp-tree.h

@@ -539,7 +539,6 @@ struct GTY(()) lang_identifier {
   cxx_binding *bindings;
   tree class_template_info;
   tree label_value;
-  bool oracle_looked_up;
 };
 
 /* Return a typed pointer version of T if it designates a