[Bug target/79354] [7 Regression] -mcpu=power8 -O2 generates power9 instruction on powerpc64le-linux

[amodra at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79354

--- Comment #6 from Alan Modra <amodra at gmail dot com> ---
Regression tested powerpc64le-linux successfully.