app-crypt/efitools: Fix building with GCC 15 by including stdbool.h

I'm not sure whether this is the best approach. I tried adding various -std
flags, but this broke more than it fixed. With upstream being dead, this should
possibly be last-rited in favour of virt-firmware, which is a better replacement
for most of the functionality here.

Closes: https://bugs.gentoo.org/955698
Signed-off-by: James Le Cuirot <chewi@gentoo.org>

app-crypt/efitools/efitools-1.9.2-r1.ebuild

@@ -1,4 +1,4 @@
-# Copyright 1999-2023 Gentoo Authors
+# Copyright 1999-2025 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
 EAPI=8
@@ -31,6 +31,7 @@ BDEPEND="
 PATCHES=(
 	"${FILESDIR}"/1.9.2-clang16.patch
 	"${FILESDIR}"/1.9.2-Makefile.patch
+	"${FILESDIR}"/1.9.2-gcc15.patch
 )
 
 src_prepare() {

app-crypt/efitools/files/1.9.2-gcc15.patch

@@ -0,0 +1,20 @@
+https://bugs.gentoo.org/955698
+
+--- a/lib/asn1/typedefs.h
++++ b/lib/asn1/typedefs.h
+@@ -34,6 +34,7 @@
+ #include <stdio.h>
+ #include <stdlib.h>
+ #include <stdarg.h>
++#include <stdbool.h>
+ #include <sys/stat.h>
+ #include <sys/types.h>
+ #include <unistd.h>
+@@ -52,7 +53,6 @@
+ 
+ #endif
+ 
+-typedef unsigned char bool;
+ typedef unsigned int u_int;
+ 
+ #define DBG1(s...)