PR c++/50473
	* decl.c (cp_finish_decl): Don't try to process a non-dependent
	constant initializer for a reference.
	* pt.c (value_dependent_expression_p): A reference is always
	dependent.
	* call.c (extend_ref_init_temps_1): Also clear TREE_SIDE_EFFECTS
	on any NOP_EXPRs.

From-SVN: r217672