Make like() and unlike() in t/test.pl refuse non-qr// arguments

As I noted in v5.21.1-12-g826af13 we have subtle bugs in the test suite
because you can do e.g. like($@, '') now which'll be a passing test even
when we have an error, because $@ =~ // will be true.

I'm just changing t/test.pl to not accept non-Regexp arguments, and
fixing up a bunch of test failures that resulted from that. There might
still be more of these in tests that I'm just not running, I've also
changed some of these from $str =~ /foo/ to $str eq 'foo'
(i.e. s/like/is/) in cases where that appeared to work, but it might
break some systems.

Let's just find that out via the smokers.

1 files changed, 2 insertions, 2 deletions

diff --git a/dist/IO/t/io_taint.t b/dist/IO/t/io_taint.t
index 5740353e77..7c3ffe6881 100644
--- a/dist/IO/t/io_taint.t
+++ b/dist/IO/t/io_taint.t
@@ -33,7 +33,7 @@ chop(my $unsafe = <$x>);
 eval { kill 0 * $unsafe };
 SKIP: {
   skip($^O) if $^O eq 'MSWin32' or $^O eq 'NetWare';
-  like($@, '^Insecure');
+  like($@, qr/^Insecure/);
 }
 $x->close;
 
@@ -44,7 +44,7 @@ $x->untaint;
 ok(!$?); # Calling the method worked
 chop($unsafe = <$x>);
 eval { kill 0 * $unsafe };
-unlike($@,'^Insecure');
+unlike($@,qr/^Insecure/);
 $x->close;
 
 TODO: {