Restrict gcc.dg/rtl/aarch64/pr113295-1.c to aarch64

I keep forgetting that gcc.dg/rtl is the one testsuite where
tests in target-specific subdirectories aren't automatically
restricted to that target.

gcc/testsuite/
	* gcc.dg/rtl/aarch64/pr113295-1.c: Restrict to aarc64*-*-*.