`perl` rootless patch incomplete

[L1ghtmann]

When attempting to use Perl's spawn(), I am getting cannot execute errors as it's looking for /bin/sh.

Relevant test script: https://github.com/theos/theos/blob/16da692ea93ecc80ecd7d7e904a62e378a0d58be/bin/swift-bootstrapper.pl

Error: Can't exec "/bin/sh": No such file or directory at $THEOS/bin/swift-bootstrapper.pl line 17

Line 17 being

my $swift_version = `$swift_command --version 2>/dev/null`;

The same applies for lines 29 & 33, which are also shell commands.

This same error then pops for lines 82 & 83 which call system():

system($print_command);
system($build_command) == 0 || die("Failed to build $project_name: command failed: $build_command\n");

Setup: iP7 15.8 Rootless