* config/nvptx/nvptx.md (allocate_stack): Emit sorry during
	expansion.
	* config/nvptx/nvptx.c (nvptx_declare_function_name): Look at
	crtl->stack_alignment_needed to determine alignment.
	(nvptx_get_drap_rtx): New.
	(TARGET_GET_DRAP_RTX): Override.
	* config/nvptx/nvptx.h (MAX_STACK_ALIGNMENT): Set.

From-SVN: r227084