JIT: additional optimizations

[pguyot]

Make imported functions available to JIT compiler Optimize +/2 and -/2 as well as < and > using types.

These changes are made under both the "Apache 2.0" and the "GNU Lesser General Public License 2.1 or later" license terms (dual license).

SPDX-License-Identifier: Apache-2.0 OR LGPL-2.1-or-later