* gcc.target/i386/pr32000-2.c: Use dg-skip-if for target expression.
	* gcc.target/i386/stackalign/return-3.c: Ditto.
	* gcc.target/sparc/ultrasp3.c: Ditto.
	* lib/target-supports-dg.exp (dg-require-effective-target): Error
	if argument is not a single effective-target keyword.

From-SVN: r139039