app-arch/arc: port to EAPI 7

Signed-off-by: Sam James <sam@gentoo.org>

app-arch/arc/arc-5.21p.ebuild

@@ -1,7 +1,7 @@
-# Copyright 1999-2020 Gentoo Authors
+# Copyright 1999-2021 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
-EAPI=6
+EAPI=7
 
 inherit toolchain-funcs
 
@@ -12,7 +12,6 @@ SRC_URI="mirror://sourceforge/${PN}/${P}.tar.gz"
 LICENSE="GPL-2"
 SLOT="0"
 KEYWORDS="~alpha amd64 ~hppa ppc ppc64 sparc x86 ~amd64-linux ~x86-linux ~ppc-macos ~x86-solaris"
-IUSE=""
 
 PATCHES=(
 	"${FILESDIR}"/${PN}-5.21m-darwin.patch

app-arch/arc/files/arc-5.21m-darwin.patch

@@ -1,5 +1,5 @@
---- arc-5.21m/tmclock.c
-+++ arc-5.21m/tmclock.c
+--- a/tmclock.c
++++ b/tmclock.c
 @@ -14,7 +14,7 @@
  /* Julian day number of the Unix* clock's origin, 01 Jan 1970. */
  #define JD1970 2440587L

app-arch/arc/files/arc-5.21o-interix.patch

@@ -1,6 +1,5 @@
-diff -ru arc-5.21o.orig/arcdos.c arc-5.21o/arcdos.c
---- arc-5.21o.orig/arcdos.c	2008-03-30 15:44:53 +0200
-+++ arc-5.21o/arcdos.c	2008-03-30 15:45:51 +0200
+--- a/arcdos.c
++++ b/arcdos.c
 @@ -30,7 +30,7 @@
  #if	UNIX
  #include <sys/types.h>