[nvptx] Rename worker_bcast variables to oacc_bcast

[nvptx] Rename worker_bcast variables to oacc_bcast

Rename worker_bcast variables to oacc_bcast, avoiding worker terminology.

Build and reg-tested on x86_64 with nvptx accelerator.

2018-12-19  Tom de Vries  <tdevries@suse.de>

	* config/nvptx/nvptx.c (worker_bcast_size): Rename as
	oacc_bcast_size.
	(worker_bcast_align): Rename as oacc_bcast_align.
	(worker_bcast_sym): Rename as oacc_bcast_sym.
	(nvptx_option_override): Update usage of oacc_bcast_*.
	(struct wcast_data_t): Rename as broadcast_data_t.
	(nvptx_gen_wcast): Update type of data argument and usage of
	oacc_bcast_align.
	(wprop_gen): Update type of data_ and usage of oacc_bcast_align.
	(nvptx_wpropagate): Update type of data and usage of
	oacc_bcast_{sym,size}.
	(nvptx_single): Update type of data and usage of oacc_bcast_size.
	(nvptx_file_end): Update usage of oacc_bcast_{sym,align,size}.

From-SVN: r267259