PR c++/82357 - bit-field in template

	* tree.c (cp_stabilize_reference): Just return a NON_DEPENDENT_EXPR.

From-SVN: r253739

gcc/cp/ChangeLog

+2017-10-13  Jason Merrill  <jason@redhat.com>
+
+	PR c++/82357 - bit-field in template
+	* tree.c (cp_stabilize_reference): Just return a NON_DEPENDENT_EXPR.
+
 2017-10-13  David Malcolm  <dmalcolm@redhat.com>
 
 	* cp-tree.h (maybe_show_extern_c_location): New decl.

gcc/cp/tree.c

@@ -333,6 +333,10 @@ cp_stabilize_reference (tree ref)
 {
   switch (TREE_CODE (ref))
     {
+    case NON_DEPENDENT_EXPR:
+      /* We aren't actually evaluating this.  */
+      return ref;
+
     /* We need to treat specially anything stabilize_reference doesn't
        handle specifically.  */
     case VAR_DECL:

gcc/testsuite/g++.dg/template/bitfield4.C

+// PR c++/82357
+
+template <typename> struct A {
+  A() { x |= 0; }
+  int x : 8;
+};

gcc/testsuite/g++.dg/template/cast4.C

+template <class T> void f()
+{
+  static_cast<int&>(42);	// { dg-error "static_cast" }
+}