re PR debug/40012 (Revision 146817 generated bad debug info for local variables)
PR debug/40012
* cfgexpand.c (set_rtl): Store place also in DECL_RTL, if all
partitions use the same.
(expand_one_var): Deal with DECL_RTL sometimes begin set also
for basevars of SSA_NAMEs.
(expand_used_vars): Reset TREE_USED for basevars of SSA_NAMEs,
to not expand them twice.
(gimple_expand_cfg): Clear DECL_RTL for those decls that have
multiple places.