[Bug target/97107] libgo fails to build for power10

[amodra at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97107

--- Comment #1 from Alan Modra <amodra at gmail dot com> ---
Created attachment 49241
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=49241&action=edit
fix under test