reload1.c (reload_cse_noop_set_p): Return false if mode of SET_DEST is not the same as that returned by...

* reload1.c (reload_cse_noop_set_p): Return false if mode of
SET_DEST is not the same as that returned by...
* cselib.h (cselib_reg_set_mode): ... new function.
* cselib.c (cselib_reg_set_mode): Define it.
(REG_VALUES): Document semantics of first element as set mode.
(cselib_subst_to_values): Skip first element if ELT is NULL.
(cselib_lookup): Likewise.  Insert past the first element.
(cselib_invalidate_regno): NULLify first element.
(cselib_record_set): Set first element.

From-SVN: r65713