VMS libtestutil: look for lower case "main"

Reviewed-by: NTim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/7208)

Configurations/descrip.mms.tmpl

@@ -1034,7 +1034,9 @@ EOF
                                  "\@ WRITE OPT_FILE \"$x" } @objs).
           "\"";
       my $write_opt2 =
-          join("\n\t", map { my @lines = ();
+          join("\n\t", map { my @lines = (
+                                 "\ WRITE OPT_FILE \"CASE_SENSITIVE=YES\""
+                             );
                              my $x = $_ =~ /\[/ ? $_ : "[]".$_;
                              if ($x =~ m|\.EXE$|) {
                                  push @lines, "\@ WRITE OPT_FILE \"$x/SHARE\"";

test/build.info

@@ -17,10 +17,10 @@ IF[{- !$disabled{tests} -}]
   DEPEND[libtestutil.a]=../libcrypto
 
   # Special hack for descrip.mms to include the MAIN object module
-  # explicitly.  This will only be done if there isn't a MAIN in the
+  # explicitly.  This will only be done if there isn't a 'main' in the
   # program's object modules already.
   BEGINRAW[descrip.mms]
-INCLUDE_MAIN___test_libtestutil_OLB = /INCLUDE=MAIN
+INCLUDE_MAIN___test_libtestutil_OLB = /INCLUDE=main
   ENDRAW[descrip.mms]
 
   PROGRAMS_NO_INST=\