[Bug rtl-optimization/64539] [5 regression] cprop_hardreg does not respect clobbers in C_I_F_U

[vries at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64539

--- Comment #3 from vries at gcc dot gnu.org ---
Created attachment 34411
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34411&action=edit
Tentative patch