[Bug bootstrap/105218] [12 regression] bootstrap build error in mpc in stage3

[jakub at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105218

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 52783
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52783&action=edit
gcc12-pr105218.patch

Untested fix.