[NFC] Update some PPC tests marked as auto-generated

Update CodeGen regression tests with marker at first line telling it's
auto-generated by the script, under PowerPC directory. For some reason,
these tests are generated but manually written, which makes things
unclear when someone's change affecting them.

However, some tests only show simple change after re-generated, like
extra blank lines, disappearing '.localentry', etc. Besides, some tests
are generated but added checks for debug output. This commit doesn't try
updating them.