[arm] Fix gcc.target/arm/xor-and.c

[arm] Fix gcc.target/arm/xor-and.c

This test is naughty because it doesn't use the proper effective target checks
and add-options mechanisms for setting a Thumb1 target, which leads to Thumb1 hard-float errors
when testing a toolchain configured with --with-cpu=cortex-a15 --with-fpu=neon-vfpv4 --with-float=hard --with-mode=thumb.

This patch fixes that in the obvious way.

	* gcc.target/arm/xor-and.c: Fix armv6 effective target checks
	and options.

From-SVN: r256782