dev-java/icedtea: Always disable PCH on PaX systems, bug #601016

I will add this to 7.2 when it supports disabling PCH in 7.2.7.0.

Package-Manager: Portage-2.3.4, Repoman-2.3.2

dev-java/icedtea/icedtea-3.3.0.ebuild

@@ -1,5 +1,6 @@
 # Copyright 1999-2017 Gentoo Foundation
 # Distributed under the terms of the GNU General Public License v2
+
 # Build written by Andrew John Hughes (gnu_andrew@member.fsf.org)
 
 EAPI="6"
@@ -280,6 +281,13 @@ src_configure() {
 		config+=" --disable-ccache"
 	fi
 
+	# PaX breaks pch, bug #601016
+	if use pch && ! host-is-pax; then
+		config+=" --enable-precompiled-headers"
+	else
+		config+=" --disable-precompiled-headers"
+	fi
+
 	config+=" --with-parallel-jobs=$(makeopts_jobs)"
 
 	unset JAVA_HOME JDK_HOME CLASSPATH JAVAC JAVACFLAGS
@@ -310,7 +318,6 @@ src_configure() {
 		$(use_enable doc docs) \
 		$(use_enable kerberos system-kerberos) \
 		$(use_with pax_kernel pax "${EPREFIX}/usr/sbin/paxmark.sh") \
-		$(use_enable pch precompiled-headers) \
 		$(use_enable sctp system-sctp) \
 		$(use_enable smartcard system-pcsc) \
 		$(use_enable sunec) \