gimple-parser.c (c_parser_gimple_binary_expression): Avoid building IL when arguments are error_mark_node.

2017-02-10  Prasad Ghangal  <prasad.ghangal@gmail.com>
	Richard Biener  <rguenther@suse.de>

	* gimple-parser.c (c_parser_gimple_binary_expression): Avoid
	building IL when arguments are error_mark_node.
	(c_parser_gimple_unary_expression): Likewise.
	(c_parser_gimple_if_stmt): Likewise.
	(c_parser_gimple_switch_stmt): Likewise.
	(c_parser_gimple_return_stmt): Likewise.
	(c_parser_parse_ssa_name): When name lookup fails do not build
	an SSA name.  Use undeclared rather than not declared in error
	reporting.

	* gcc.dg/gimplefe-error-1.c: New testcase.
	* gcc.dg/gimplefe-error-2.c: New testcase.
	* gcc.dg/gimplefe-error-3.c: New testcase.

Co-Authored-By: Richard Biener <rguenther@suse.de>

From-SVN: r245326