[Bug target/91886] [10 regression] powerpc64 impossible constraint in asm

[nsz at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91886

--- Comment #30 from nsz at gcc dot gnu.org ---
i think it is not the end of the world if the asm constraint api
changes in this case: fixing musl is easy because it's not super
important to optimize fmin, fminf, fmax, fmaxf in libc (if it were
important then gcc should inline them instead of calling into libc,
currently it seems gcc is not able to do that without -ffast-math).

the change breaks the build of old musl releases with new gcc,
so as a general principle it makes more sense to me to keep
documented apis working (e.g. when glibc removed ustat, the gcc
devs asked for 5 years advance notice via deprecation warnings),
but it's up to the gcc maintainers to decide.