Issue #19753: Fix test_gdb on SystemZ buildbot, ignore warnings

Lib/test/test_gdb.py

@@ -163,6 +163,10 @@ class DebuggerTests(unittest.TestCase):
             'linux-gate.so',
             'Do you need "set solib-search-path" or '
             '"set sysroot"?',
+            'warning: Source file is more recent than executable.',
+            # Issue #19753: missing symbols on System Z
+            'Missing separate debuginfo for ',
+            'Try: zypper install -C ',
             )
         for line in errlines:
             if not line.startswith(ignore_patterns):