TypeError on non-existent file in whitelist

[krakjoe]

Q	A
php-code-coverage version	7.0.0
PHP version	7.2/7.3
Driver	N/A
Xdebug version (if used)	N/A
Installation Method	N/A
Usage Method	PHPUnit
PHPUnit version (if used)	8.0.0

When a file present in the whitelist is not accessible on disk, the whitelist contains int, when CodeCoverage::initializeData iterates over the whitelist, it passes an int to Filter::isFile which raises TypeError