Fix earlier ChangeLog entry to give Igor credit, add testcases.

Fix earlier ChangeLog entry to give Igor credit, add testcases.

2016-12-01  Cary Coutant  <ccoutant@gmail.com>
	    Igor Kudrin  <ikudrin@accesssoftek.com>

	PR gold/20717
	* script-sections.cc (Script_sections): Set *keep to false when
	no match.

2016-12-11  Igor Kudrin  <ikudrin@accesssoftek.com>

	PR gold/20717
	* testsuite/Makefile.am (pr20717): New test.
	* testsuite/Makefile.in: Regenerate.
	* testsuite/pr20717.c: New test source file.
	* testsuite/pr20717.sh: New test script.
	* testsuite/pr20717.t: New test linker script.