[Bug libstdc++/103407] [12 regression] abi_check FAILs on Solaris

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103407

--- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> ---
This fixes the abi check FAIL on Solaris 11.3, I don't have access to 11.4 to
try it.