IPA ICF: Fix for PR ipa/64146

gcc/ChangeLog:

2014-12-10  Martin Liska  <mliska@suse.cz>

	PR ipa/64146
	* ipa-icf.c (sem_function::merge): Check for
	decl_binds_to_current_def_p is newly added to merge operation.

gcc/testsuite/ChangeLog:

2014-12-10  Martin Liska  <mliska@suse.cz>

	* g++.dg/ipa/pr64146.C: New test.