dev-embedded/avarice: workaround build failure with GCC 11

Closes: https://bugs.gentoo.org/788295
Signed-off-by: Sam James <sam@gentoo.org>

dev-embedded/avarice/avarice-2.14.ebuild

@@ -1,8 +1,10 @@
-# Copyright 1999-2020 Gentoo Authors
+# Copyright 1999-2021 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
 EAPI=7
 
+inherit flag-o-matic
+
 DESCRIPTION="Interface for GDB to Atmel AVR JTAGICE in circuit emulator"
 HOMEPAGE="http://avarice.sourceforge.net/"
 SRC_URI="mirror://sourceforge/${PN}/${P}.tar.bz2"
@@ -13,6 +15,13 @@ KEYWORDS="~amd64 ~x86"
 
 PATCHES=( "${FILESDIR}"/${P}-broken-__unused-macro.patch )
 
+src_configure() {
+	# bug #788295
+	append-cxxflags -std=c++14
+
+	default
+}
+
 src_install() {
 	default
 	dodoc doc/*.txt