tests: Warn not fail when reading invalid pickle status files
tests: Warn not fail when reading invalid pickle status files

With this change, the test script will output a warning when it reads
an incomplete (e.g., when a regression is still running) or corrupt
status file instead of throwing an exception. When the scipt is used
to show the results the corrupt file is skipped; when it is used to
test if all regressions run successfully it will return an error value
(2).

Change-Id: Ie7d9b457b200e3abc7ae6238e3efbf3d18cf4297
Signed-off-by: Andreas Sandberg <c9f5686ee5bd561c93f9de79681eee75bfa7f36e@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/2320
Reviewed-by: Jason Lowe-Power <68c46a606457643eab92053c1c05574abb26f861@lowepower.com>
Maintainer: Jason Lowe-Power <68c46a606457643eab92053c1c05574abb26f861@lowepower.com>

Weil0ng/gem5,HwisooSo/gemV-update,gem5/gem5,rallylee/gem5,TUD-OS/gem5-dtu,TUD-OS/gem5-dtu,gedare/gem5,powerjg/gem5-ci-test,HwisooSo/gemV-update,gem5/gem5,Weil0ng/gem5,powerjg/gem5-ci-test,rallylee/gem5,Weil0ng/gem5,TUD-OS/gem5-dtu,sobercoder/gem5,gedare/gem5,TUD-OS/gem5-dtu,HwisooSo/gemV-update,gem5/gem5,gem5/gem5,sobercoder/gem5,TUD-OS/gem5-dtu,sobercoder/gem5,gedare/gem5,powerjg/gem5-ci-test,gem5/gem5,powerjg/gem5-ci-test,gedare/gem5,sobercoder/gem5,rallylee/gem5,gem5/gem5,sobercoder/gem5,gedare/gem5,rallylee/gem5,TUD-OS/gem5-dtu,sobercoder/gem5,powerjg/gem5-ci-test,gedare/gem5,HwisooSo/gemV-update,gedare/gem5,rallylee/gem5,powerjg/gem5-ci-test,gem5/gem5,Weil0ng/gem5,rallylee/gem5,Weil0ng/gem5,Weil0ng/gem5,powerjg/gem5-ci-test,HwisooSo/gemV-update,sobercoder/gem5,HwisooSo/gemV-update,HwisooSo/gemV-update,TUD-OS/gem5-dtu,Weil0ng/gem5,rallylee/gem5