[Bug rtl-optimization/91347] [7/8/9/10 Regression] pointer_string in linux vsprintf.c is miscompiled when sibling calls are optimized

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91347

--- Comment #8 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
Created attachment 46721
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=46721&action=edit
Tentative fix

Please give it a try on the PA.