re PR c++/47208 ([C++0x] ICE: in decl_constant_var_p, at cp/decl2.c:3563 with missing #include <initializer_list>)

PR c++/47208

gcc/cp/

	PR c++/47208
	* pt.c (do_auto_deduction): Do not mention error_mark_node in
	diagnostics.
	* semantics.c (finish_id_expression): Do not pass erroneous decl
	to decl_constant_var_p.

gcc/testsuite/

	PR c++/47208
	* g++.dg/cpp0x/auto21.C: New test.

From-SVN: r170268