use 5.020;
use feature 'experimental::signatures';
no warnings 'experimental::signatures';

my %module_map = (
    'List/Util.pm' => '/some/path/to/perl/modules',
    'Scalar/Util.pm' => '/some/other/path/to/perl/modules',
);

sub find_correct_module( $self, $module_file ) {
    my $real_module = $module_map{ $module_file } // $module_file;
    open my $fh, '<', $real_module or croak $!;
    return $fh
}

BEGIN {
    unshift @INC, \&find_correct_module;
}