[Bug c/77530] optimization prevents excess precision from being removed with x86/amd64 long double and rounding to 53 bits

[vincent-gcc at vinc17 dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77530

--- Comment #2 from Vincent Lefèvre <vincent-gcc at vinc17 dot net> ---
This seems to depend on the NetBSD version. The default rounding precision has
changed in NetBSD 7.0: https://www.netbsd.org/changes/changes-7.0.html