Backport 2.7: Use "#!/usr/bin/env perl" as shebang line.
diff --git a/tests/scripts/recursion.pl b/tests/scripts/recursion.pl
index 3ad42b1..431e592 100755
--- a/tests/scripts/recursion.pl
+++ b/tests/scripts/recursion.pl
@@ -1,4 +1,4 @@
-#!/usr/bin/perl
+#!/usr/bin/env perl
 
 # Find functions making recursive calls to themselves.
 # (Multiple recursion where a() calls b() which calls a() not covered.)