[PATCH] Fix PR rtl-opt/38281 ICE in reg_referenced_p with combine

[Eric Botcazou]

>   The problem here is that distribute_notes assumes that if the i2 is
> not NULL, INSN_P is true but it could have been a deleted instruction
> note which case we could get an ICE on PATTERN of it (or get a NULL
> from it without RTL checking enabled).

i2 is not NULL because newi2pat is not either, which is a little strange if i2 
has been deleted.  Why is newi2pat not NULL?

-- 
Eric Botcazou