C++ PATCH to fix typo in cp-tree.h

[Marek Polacek]

We don't have INDIRECT_EXPR.

Applying as obvious.

2018-08-21  Marek Polacek  <pola...@redhat.com>

        * cp-tree.h: Fix typo.

--- gcc/cp/cp-tree.h
+++ gcc/cp/cp-tree.h
@@ -3656,7 +3656,7 @@ struct GTY(()) lang_decl {
   (LANG_DECL_FN_CHECK (FUNCTION_DECL_CHECK (NODE))     \
    ->u.saved_language_function)
 
-/* True if NODE is an implicit INDIRECT_EXPR from convert_from_reference.  */
+/* True if NODE is an implicit INDIRECT_REF from convert_from_reference.  */
 #define REFERENCE_REF_P(NODE)                          \
   (INDIRECT_REF_P (NODE)                               \
    && TREE_TYPE (TREE_OPERAND (NODE, 0))               \