[Bug c++/70744] preincrements possibly double-evaluated in GNU ternaries

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70744

--- Comment #4 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
A possible fix seems to be
--- a/gcc/tree.c
+++ b/gcc/tree.c
@@ -4255,6 +4255,12 @@ stabilize_reference (tree ref)
     volatiles.  */
       return stabilize_reference_1 (ref);

+    case POSTDECREMENT_EXPR:
+    case POSTINCREMENT_EXPR:
+    case PREDECREMENT_EXPR:
+    case PREINCREMENT_EXPR:
+      return stabilize_reference_1 (ref);
+
       /* If arg isn't a kind of lvalue we recognize, make no change.
     Caller should recognize the error for an invalid lvalue.  */
     default:

but not sure if these belong into stabilize_reference ...