This script compared paths relative to the report directory to test for exclusion,
meaning the directory exclusions did not work properly, as they were relative to
the project root.
Fix this by creating absolute paths through the combination of:
'git ls-files --full-name'and 'git rev-parse --show-toplevel'
This is a backport of core#15258 [1/2]
https://github.com/bitcoin/bitcoin/pull/15258/commits/2434ab5c2afd61aa0cf81f80b1b236ea52d1d20d