[Bug c++/77427] [6/7 Regression] ice when canonical types differ for identical types

[vries at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77427

--- Comment #4 from Tom de Vries <vries at gcc dot gnu.org> ---
This fixes the ICE:
...
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 4531647..f13790f 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -10551,6 +10551,8 @@ ix86_build_builtin_va_list_64 (void)
   TYPE_ATTRIBUTES (record) = tree_cons (get_identifier ("sysv_abi va_list"),
                                        NULL_TREE, TYPE_ATTRIBUTES (record));

+  SET_TYPE_STRUCTURAL_EQUALITY (record);
+
   /* The correct type is an array type of one element.  */
   return build_array_type (record, build_index_type (size_zero_node));
 }
...