[llvm] [PowerPC][NFC] Allow different orders of .extern in some test cases (PR #89714)

[Eli Friedman via llvm-commits]

efriedma-quic wrote:

We actually care that the output of the compiler is deterministic, not just that the tests pass.  This is important for reproducible builds.

So I don't think changing the CHECK lines is right here.  Probably the compiler should sort the symbols before it outputs them, or something like that.

https://github.com/llvm/llvm-project/pull/89714