The attached patch fixes two test_gdb problems that can occur under some circumstances:

- With new GDB (I think version >= 7.4.0, but I'm not sure about the precise version), GDB sometimes prints "entry-values" for variables, which can lead to failures like: "AssertionError: 'v@entry=()' != '()'". The cure for that is using "set print entry-values no" in GDB. I think this is also the root cause of issue 17126.

- While building on ppc64 little endian for Fedora, we experienced GDB printing program counter for the first frame, which breaks regular expressions matching in tests, e.g. instead of

#0 in PyObject_Print

the lines can look like

#0 0x00003fffb7dd1798 in PyObject_Print

I've talked to Fedora's GDB maintainer and I've been told that this can happen and it's not a GDB bug - GDB does not guarantee this. Therefore the second part of the attached patch turns printing program counters for *all* frames using "set print address off" to achieve same GDB output everywhere.