newlib: setup newlib sources

.gitmodules

@@ -5,3 +5,6 @@
 [submodule "third_party/src/github.com/0intro/drawterm"]
 	path = third_party/src/github.com/0intro/drawterm
 	url = https://github.com/JehanneOS/devtools-drawterm.git
+[submodule "cross/pkgs/newlib/src"]
+	path = cross/pkgs/newlib/src
+	url = https://github.com/JehanneOS/newlib.git

cross/pkgs/README.txt

@@ -0,0 +1,6 @@
+# Jehanne cross-compiled packages
+
+This folder contains those development tools that need to be
+cross-compiled to bootstrap a selfhosted system.
+
+Mainly this means a native compiler and its dependencies. 

cross/pkgs/newlib.sh

@@ -0,0 +1,35 @@
+#!/bin/bash
+
+# This file is part of Jehanne.
+#
+# Copyright (C) 2017 Giacomo Tesio <giacomo@tesio.it>
+#
+# Jehanne is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, version 2 of the License.
+#
+# Jehanne is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Jehanne.  If not, see <http://www.gnu.org/licenses/>.
+
+if [ "$JEHANNE" = "" ]; then
+        echo $0 requires the shell started by ./hacking/devshell.sh
+        exit 1
+fi
+
+# To create a Jehanne version of GCC, we need specific OUTDATED versions
+# of Autotools that won't compile easily in a modern Linux distro.
+
+function failOnError {
+	# $1 -> exit status on a previous command
+	# $2 -> task description
+	if [ $1 -ne 0 ]; then
+		echo "ERROR $2"
+		exit $1
+	fi
+}
+

cross/pkgs/newlib/src

@@ -0,0 +1 @@
+Subproject commit 0f0315dbffeb30149c5746dedd307dc1f12eb317