re PR debug/46724 (Wrong debug info: Invalid variable location)

re PR debug/46724 (Wrong debug info: Invalid variable location)

PR debug/46724
* function.c (assign_parms_augmented_arg_list): Name and mark
DECL of result address as NAMELESS rather than IGNORED.
(assign_parms): Set DECL_VALUE_EXPR for indirect result.
* tree.h (tree_decl_common::decl_flag_2): Document RESULT_DECL.
(DECL_HAS_VALUE_EXPR_P): Accept RESULT_DECL.
* dwarf2out.c (loc_list_from_tree) <RESULT_DECL>: Use
DECL_VALUE_EXPR.
* dbxout.c (dbxout_expand_expr) <RESULT_DECL>: Likewise.
* var-tracking.c (vt_add_function_parameter): New, split out of...
(vt_add_function_parameters): ... this.  Handle incoming
pointer to hold result.

From-SVN: r168160