re PR debug/47624 (FAIL: gcc.dg/guality/pr43077-1.c -O1 line 42 c == 3)

re PR debug/47624 (FAIL: gcc.dg/guality/pr43077-1.c  -O1  line 42 c == 3)

PR debug/47624
* var-tracking.c (loc_exp_dep_pool): New.
(vt_emit_notes): Create and release the pool.
(compute_bb_dataflow): Use value-based locations in MO_VAL_SET.
(emit_notes_in_bb): Likewise.
(loc_exp_dep_insert): Deal with NOT_ONEPART vars.
(notify_dependents_of_changed_value): Likewise.
(notify_dependents_of_resolved_value): Check that NOT_ONEPART
variables don't have a VAR_LOC_DEP_LST.
(emit_note_insn_var_location): Expand NOT_ONEPART locs that are
VALUEs or MEMs of VALUEs.

From-SVN: r188530