Add v2si support for nvptx

Add v2si support for nvptx

2017-07-19  Tom de Vries  <tom@codesourcery.com>

	* config/nvptx/nvptx-modes.def: New file.  Add V2SImode.
	* config/nvptx/nvptx.c (nvptx_ptx_type_from_mode): Handle V2SImode.
	(nvptx_vector_mode_supported): New function.  Allow V2SImode.
	(TARGET_VECTOR_MODE_SUPPORTED_P): Redefine to nvptx_vector_mode_supported.
	* config/nvptx/nvptx.md (VECIM): New mode iterator. Add V2SI.
	(mov<VECIM>_insn): New define_insn.
	(define_expand "mov<VECIM>): New define_expand.

	* gcc.target/nvptx/slp-run.c: New test.
	* gcc.target/nvptx/slp.c: New test.
	* gcc.target/nvptx/v2si-cvt.c: New test.
	* gcc.target/nvptx/v2si-run.c: New test.
	* gcc.target/nvptx/v2si.c: New test.
	* gcc.target/nvptx/vec.inc: New test.

From-SVN: r250340