Add FreeBSD-specific SONAME versions to portable OpenSSL probing.

The version of OpenSSL installed will depend on the version of FreeBSD and
whether OpenSSL has been updated from the FreeBSD Ports collection.

The order of attempted loading is:
    libssl.so.11 (ports)
    libssl.so.111 (base FreeBSD using OpenSSL 1.1.1)
    libssl.so.8 (base FreeBSD using OpenSSL 1.0.2)

src/libraries/Native/Unix/System.Security.Cryptography.Native/opensslshim.c

@@ -97,6 +97,23 @@ static bool OpenLibrary()
         DlOpen(MAKELIB("10"));
     }
 
+    // FreeBSD uses a different suffix numbering convention.
+    // Current supported FreeBSD releases should use the order .11 -> .111 -> .8
+    if (libssl == NULL)
+    {
+        DlOpen(MAKELIB("11"));
+    }
+
+    if (libssl == NULL)
+    {
+        DlOpen(MAKELIB("111"));
+    }
+
+    if (libssl == NULL)
+    {
+        DlOpen(MAKELIB("8"));
+    }
+
     return libssl != NULL;
 }