This patch removes the explicit reference to the 'perl' binary,
such that OpenSSL does not retain a reference to Perl.

The 'c_rehash' program is seldom used, but it is used nonetheless
to create symbolic links to certificates, for instance in the 'nss-certs'
package.

diff --git a/tools/c_rehash.in b/tools/c_rehash.in
index 421fd89208..93aca4e168 100644
--- a/tools/c_rehash.in
+++ b/tools/c_rehash.in
@@ -1,4 +1,6 @@
-#!{- $config{HASHBANGPERL} -}
+eval '(exit $?0)' && eval 'exec perl -wS "$0" ${1+"$@"}'
+  & eval 'exec perl -wS "$0" $argv:q'
+    if 0;
 
 # {- join("\n# ", @autowarntext) -}
 # Copyright 1999-2018 The OpenSSL Project Authors. All Rights Reserved.