[Bug middle-end/85344] constants with the sign bit set causes sign extension which is unexpected but not documented in the user documentation

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85344

--- Comment #22 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
The last time trunc_int_for_mode changed for the sign extendness was in 2001,
by g:5b0d91c39237 .

This changed it to sign extend it for all modes rather than just 32bits mode
(while on a 64bit host; back when HWI could be either 32bit or 64bit).