dev-libs/cygwin: drop prepstrip(), bug #587290

This disables all stripping in cygwin. As PMS does
not provide an alternative just drop stripping for now.

Reported-by: Michał Górny
Closes: https://bugs.gentoo.org/587290
Package-Manager: Portage-2.3.52, Repoman-2.3.12
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>

dev-libs/cygwin/cygwin-1.5.25.15.ebuild

@@ -1,4 +1,4 @@
-# Copyright 1999-2018 Gentoo Foundation
+# Copyright 1999-2018 Gentoo Authors
 # Distributed under the terms of the GNU General Public License v2
 
 EAPI=0
@@ -88,6 +88,5 @@ src_install() {
 	else
 		cd "${WORKDIR}"/build
 		emake install DESTDIR="${D}" || die
-		env -uRESTRICT CHOST=${CTARGET} prepallstrip
 	fi
 }