mkdef.pl: Add cmd-line flag to differentiate shared libs and DSO.

Fixes openssl#16984.

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18284)
diff --git a/Configurations/descrip.mms.tmpl b/Configurations/descrip.mms.tmpl
index c202bd4..eb00587 100644
--- a/Configurations/descrip.mms.tmpl
+++ b/Configurations/descrip.mms.tmpl
@@ -981,7 +981,7 @@
               ? '' : ' --case-insensitive';
           return <<"EOF";
 $target : $gen0 $deps $mkdef
-	\$(PERL) $mkdef$ord_ver --ordinals $gen0 --name $ord_name "--OS" "VMS"$case_insensitive > $target
+	\$(PERL) $mkdef$ord_ver --type $args{intent} --ordinals $gen0 --name $ord_name "--OS" "VMS"$case_insensitive > $target
 EOF
       } elsif (platform->isasm($args{src})) {
           #
diff --git a/Configurations/unix-Makefile.tmpl b/Configurations/unix-Makefile.tmpl
index 35f03d6..5b8340d 100644
--- a/Configurations/unix-Makefile.tmpl
+++ b/Configurations/unix-Makefile.tmpl
@@ -1549,7 +1549,7 @@
           my $ord_name = $args{generator}->[1] || $args{product};
           return <<"EOF";
 $target: $gen0 $deps \$(SRCDIR)/util/mkdef.pl
-	\$(PERL) \$(SRCDIR)/util/mkdef.pl$ord_ver --ordinals $gen0  --name $ord_name --OS $mkdef_os > $target
+	\$(PERL) \$(SRCDIR)/util/mkdef.pl$ord_ver --type $args{intent} --ordinals $gen0  --name $ord_name --OS $mkdef_os > $target
 EOF
       } elsif (platform->isasm($args{src})) {
           #
diff --git a/Configurations/windows-makefile.tmpl b/Configurations/windows-makefile.tmpl
index a195bd5..5d87445 100644
--- a/Configurations/windows-makefile.tmpl
+++ b/Configurations/windows-makefile.tmpl
@@ -744,7 +744,7 @@
               $args{generator}->[1] || platform->dsoname($args{product});
           return <<"EOF";
 $target: $gen0 $deps $mkdef
-	"\$(PERL)" "$mkdef"$ord_ver --ordinals $gen0 --name $ord_name --OS windows > $target
+	"\$(PERL)" "$mkdef"$ord_ver --type $args{intent} --ordinals $gen0 --name $ord_name --OS windows > $target
 EOF
       } elsif (platform->isasm($args{src})) {
           #
diff --git a/util/mkdef.pl b/util/mkdef.pl
index a1c76f7..c84fb33 100755
--- a/util/mkdef.pl
+++ b/util/mkdef.pl
@@ -29,6 +29,7 @@
 my $ordinals_file = undef;      # the ordinals file to use
 my $version = undef;            # the version to use for the library
 my $OS = undef;                 # the operating system family
+my $type = 'lib';               # either lib or dso
 my $verbose = 0;
 my $ctest = 0;
 my $debug = 0;
@@ -40,6 +41,7 @@
            'ordinals=s' => \$ordinals_file,
            'version=s'  => \$version,
            'OS=s'       => \$OS,
+           'type=s'     => \$type,
            'ctest'      => \$ctest,
            'verbose'    => \$verbose,
            # For VMS
@@ -48,6 +50,8 @@
 
 die "Please supply arguments\n"
     unless $name && $ordinals_file && $OS;
+die "--type argument must be equal to 'lib' or 'dso'"
+    if $type ne 'lib' && $type ne 'dso';
 
 # When building a "variant" shared library, with a custom SONAME, also customize
 # all the symbol versions.  This produces a shared object that can coexist
@@ -101,7 +105,7 @@
 #
 (my $SO_VARIANT = uc($target{"shlib_variant"} // '')) =~ s/\W/_/g;
 
-my $libname = platform->sharedname($name);
+my $libname = $type eq 'lib' ? platform->sharedname($name) : platform->dsoname($name);
 
 my %OS_data = (
     solaris     => { writer     => \&writer_linux,