Cope with absent Perl modules threads and Thread::Queue.

* automake.in: Instead of `use threads', use `require threads;
import threads' inside a BEGIN section.  Likewise for
Thread::Queue.
* lib/Automake/ChannelDefs.pm (Automake::ChannelDefs): Likewise.
* lib/Automake/tests/Condition-t.pl: Likewise.
* lib/Automake/tests/DisjConditions-t.pl: Likewise.
* configure.ac: Likewise, use `require' and `import'.
Report by Eric Blake, fix suggested by Ben Pfaff.

Signed-off-by: Ralf Wildenhues <Ralf.Wildenhues@gmx.de>

1 files changed, 4 insertions, 2 deletions

diff --git a/configure b/configure
index 9452a620f..73994bd03 100755
--- a/configure
+++ b/configure
@@ -2390,8 +2390,10 @@ else
     use Config;
     if ($Config{useithreads})
       {
-	use threads;
-	use Thread::Queue;
+	require threads;
+	import threads;
+	require Thread::Queue;
+	import Thread::Queue;
 	exit 0;
       }
     exit 1;' >&5 2>&1