[Bug testsuite/88697] New test case gcc.target/powerpc/pr88457.c in r267307 fails because of glibc requirement

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88697

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
you can add a new effective target (or adjust the existing one accordingly)