[Bug libgcc/66225] libgcc/config/rs6000/morecore.S will not build on systems with an older assembler

[meissner at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66225

--- Comment #2 from Michael Meissner <meissner at gcc dot gnu.org> ---
The proposed patch allows the big endian powerpc build to build and install.