cmov: test with miri on powerpc-unknown-linux-gnu (#1297)

Trying to catch the same bug from #1295 with the existing test suite

Author: tarcieri

.github/workflows/cmov.yml

@@ -130,8 +130,9 @@ jobs:
     strategy:
       matrix:
         target:
-          - x86_64-unknown-linux-gnu
+          - powerpc-unknown-linux-gnu
           - s390x-unknown-linux-gnu
+          - x86_64-unknown-linux-gnu
     steps:
       - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@nightly