tools: output include guards in mk-ca-bundle.pl

Commit eff96d3 ("src: add include guards to internal headers") adds
include guards.  Update tools/mk-ca-bundle.pl to output them when
generating src/node_root_certs.h.

PR-URL: https://github.com/nodejs/node/pull/7363
Reviewed-By: Fedor Indutny <fedor.indutny@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>

tools/mk-ca-bundle.pl

@@ -203,6 +203,7 @@ my $skipnum = 0;
 my $start_of_cert = 0;
 
 open(TXT,"$txt") or die "Couldn't open $txt: $!\n";
+print CRT "#if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS\n";
 while (<TXT>) {
   if (/\*\*\*\*\* BEGIN LICENSE BLOCK \*\*\*\*\*/) {
     print CRT;
@@ -310,6 +311,7 @@ while (<TXT>) {
     }
   }
 }
+print CRT "#endif  // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS\n";
 close(TXT) or die "Couldn't close $txt: $!\n";
 close(CRT) or die "Couldn't close $crt.~: $!\n";
 unless( $stdout ) {