[Bug rtl-optimization/105395] Invalid reload of atomic operation

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105395

--- Comment #1 from Drea Pinski <pinskia at gcc dot gnu.org> ---
Created attachment 64263
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=64263&action=edit
Testcase without an uninitialized reg

This adds the setting of (reg:SI <2>) so it is initialized.