libdwelf: New DWARF ELF Low-level Functions. Add dwelf_elf_gnu_debuglink.

New public header elfutils/libdwelf.h for low-level DWARF/ELF helper
functions.  The new function dwelf_elf_gnu_debuglink returns the name and
crc as found in the .gnu_debuglink section of an ELF file.

Signed-off-by: Mark Wielaard <mjw@redhat.com>
diff --git a/tests/run-debuglink.sh b/tests/run-debuglink.sh
new file mode 100755
index 0000000..42a816c
--- /dev/null
+++ b/tests/run-debuglink.sh
@@ -0,0 +1,29 @@
+#! /bin/sh
+# Copyright (C) 2014 Red Hat, Inc.
+# This file is part of elfutils.
+#
+# This file 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; either version 3 of the License, or
+# (at your option) any later version.
+#
+# elfutils 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+. $srcdir/test-subr.sh
+
+# Just some random testfiles, two with, one without .gnu_debuglink
+testfiles testfile36 testfile52-32.so testfile42
+
+testrun_compare  ${abs_builddir}/debuglink testfile36 testfile52-32.so testfile42 <<\EOF
+testfile36: testfile36.debug, crc: 8c5c20a3
+testfile52-32.so: testfile52-32.so.debug, crc: b835a71d
+testfile42: <no gnu_debuglink file>
+EOF
+
+exit 0