The `set disassembly-flavor` command is only available when debugging a x86
target. On other targets, sourcing `tools/gdbinit` fails as a result.

Sadly, we have to resort to using python's exception to ignore errors and carry
on.

NOTRY=true

Change-Id: If37450ee5bca43d5edb02fa9a5b218d7992f8885
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1847353
Commit-Queue: Pierre Langlois <pierre.langlois@arm.com>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64182}