* lib/gcc-dg.exp: (dg-require-weak, dg-require-visibility,
	dg-require-alias, dg-require-gc-sections, dg-require-profiling,
	dg-require-dll, dg-require-iconv, dg-require-named-sections,
	dg-require-effective-target, dg-skip-if, dg-xfail-if, selector_opd,
	selector_list, selector_expression, dg-process-target): Move to new
	file target-supports-dg.exp.
	* lib/target-supports-dg.exp: New.

From-SVN: r94901