perl-core/Thread-Semaphore: Spread ~ on stable/dev/exp arches from perl

Spreading ~alpha ~arm ~arm64 ~hppa ~ia64 ~ppc ~ppc64 ~sparc ~x64-cygwin
from dev-lang/perl, as Thread-Semaphore is part of perl itself, and if
indeed this package doesn't work, then perl doesn't work either.

Package-Manager: Portage-2.3.40, Repoman-2.3.9

perl-core/Thread-Semaphore/Thread-Semaphore-2.120.0-r1.ebuild

@@ -1,4 +1,4 @@
-# Copyright 1999-2014 Gentoo Foundation
+# Copyright 1999-2018 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2
 
 EAPI=5
@@ -10,7 +10,7 @@ inherit perl-module
 DESCRIPTION="Thread-safe semaphores"
 
 SLOT="0"
-KEYWORDS="~amd64 ~x86"
+KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~ia64 ~ppc ~ppc64 ~sparc ~x86 ~x64-cygwin"
 IUSE=""
 
 RDEPEND="virtual/perl-threads-shared