It's not a regression but the change is really straightforward.
Tested x86-64/Linux, applied on the mainline.
2018-03-20 Eric Botcazou <ebotca...@adacore.com>
c-family/
* c-ada-spec.c (pp_ada_tree_identifier): Deal specifically with _Bool.
--
Eric Botcazou
Index: c-ada-spec.c
===================================================================
--- c-ada-spec.c (revision 258629)
+++ c-ada-spec.c (working copy)
@@ -1409,7 +1409,7 @@ pp_ada_tree_identifier (pretty_printer *
else
pp_string(buffer, s);
else
- if (!strcmp (s, "bool"))
+ if (!strcmp (s, "u_Bool") || !strcmp (s, "bool"))
{
if (package_prefix)
{