[binutils-gdb] Check for readline support in gdb.base/history-duplicates.exp.

[sergiodj+buildbot@redhat.com]

*** TEST RESULTS FOR COMMIT 0588c79688b061699500f317e193bbb3fe50c41d ***

Author: Sandra Loosemore <sandra@codesourcery.com>
Branch: master
Commit: 0588c79688b061699500f317e193bbb3fe50c41d

Check for readline support in gdb.base/history-duplicates.exp.

2015-12-14  Sandra Loosemore  <sandra@codesourcery.com>

	gdb/testsuite/
	* gdb.base/history-duplicates.exp: Skip if no readline support.