gcc-dg.exp (gcc_force_conventional_output): New global variable, default empty, -ffat-lto-objects for effective_target_lto.

	* lib/gcc-dg.exp (gcc_force_conventional_output): New global
	variable, default empty, -ffat-lto-objects for effective_target_lto.
	(gcc-dg-test-1): Add options from dg-final methods.
	* lib/scanasm.exp (scan-assembler_required_options)
	(scan-assembler-not_required_options): New procs.

From-SVN: r180972