re PR debug/36617 (Debug info for OpenMP code is almost non-existent)

re PR debug/36617 (Debug info for OpenMP code is almost non-existent)

	PR debug/36617
	* tree-cfg.c (struct move_stmt_d): Replace block field with
	orig_block and new_block fields.
	(move_stmt_r): Only set TREE_BLOCK to p->new_block if
	if it used to be NULL, p->orig_block or if p->orig_block is NULL.
	(move_block_to_fn): Replace vars_map and new_label_map arguments
	with struct move_stmt_d pointer.
	(replace_block_vars_by_duplicates): New function.
	(move_sese_region_to_fn): Add ORIG_BLOCK argument.  Adjust
	move_block_to_fn caller.  If ORIG_BLOCK is non-NULL, move over
	all subblocks of ORIG_BLOCK to the new function.  Call
	replace_block_vars_by_duplicates.
	* tree-flow.h (move_sese_region_to_fn): Adjust prototype.
	* omp-low.c (expand_omp_taskreg): Set TREE_USED on DECL_INITIAL
	BLOCK of the new function.  Adjust move_sese_region_to_fn caller.
	Prune vars with original DECL_CONTEXT from child_cfun->local_decls.
	(expand_omp): Temporarily set input_location to the location of
	region's controlling stmt.
	(lower_omp_sections, lower_omp_for): Add a BLOCK into outermost
	BIND_EXPR, push ctx->block_vars and gimplification vars into
	the BIND_EXPR and its block's BLOCK_VARS instead of directly
	into dest function.
	(lower_omp_single): Set TREE_USED on the BIND_EXPR's BLOCK if
	there are any BLOCK_VARS.
	(lower_omp_taskreg): Set BLOCK on a BIND_EXPR containing the
	OMP_PARALLEL or OMP_TASK stmt.
	(lower_omp): Save and restore input_location around the lower_omp_1
	call.

	* testsuite/libgomp.c/debug-1.c: New test.

From-SVN: r137198