In JavaScript we have a number of extra conversions not covered by
qvariant_cast. Therefore, add a method to perform a QVariant conversion
in JavaScript semantics to QJSEngine, and use that in the compiler.
Pick-to: 6.3
Fixes: QTBUG-100883
Change-Id: I8b0bfa0974bc6b339d2601fb373859bc710788c8
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>
Reviewed-by: Jarkko Koivikko <jarkko.koivikko@code-q.fi>
Ulf Hermann