[Bug lto/70955] [6/7 Regression] Wrong code generation for __builtin_ms_va_list with -flto

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70955

--- Comment #22 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to vries from comment #18)
> Created attachment 39484 [details]
> Tentative patch using attributes ms_abi/sysv_abi
> 
> not build or regression tested yet, but at least makes test-case pass.

LGTM.