[PATCH,rs6000] fix PR31535

[David Edelsohn]

gcc/
	PR 31535
	* config/rs6000/rs6000.c (small_data_operand): Vectors and floats
	are not legitimate small data references on SPE targets.

gcc/testsuite/
	PR 31535
	* gcc.target/powerpc/spe-small-data-1.c: New test.
	* gcc.target/powerpc/spe-small-data-2.c: New test.

Okay for mainline.

Thanks, David