PR debug/52001
* cselib.c (preserve_only_constants): Rename to...
(preserve_constants_and_equivs): ... this.  Split out...
(invariant_or_equiv_p): ... this.  Preserve plus expressions
of other preserved expressions too.
(cselib_reset_table): Adjust.
* var-tracking.c (reverse_op): Use canonical value to build
reverse operation.

From-SVN: r184571