Add skip_all_without_perlio() to test.pl, and use it in 8 tests.

It's a common idiom in the tests. This makes it easier to find, read, and
remove.

1 files changed, 4 insertions, 0 deletions

diff --git a/t/test.pl b/t/test.pl
index 9958356285..a09c831cb4 100644
--- a/t/test.pl
+++ b/t/test.pl
@@ -132,6 +132,10 @@ sub skip_all_without_extension {
     skip_all("$extension was not built");
 }
 
+sub skip_all_without_perlio {
+    skip_all('no PerlIO') unless PerlIO::Layer->find('perlio');
+}
+
 sub _ok {
     my ($pass, $where, $name, @mess) = @_;
     # Do not try to microoptimize by factoring out the "not ".