mozjs: fix linking issues on i586

When building for qemux86 on a x86 host, there's a possibility that the build
will try to link with incorrect libraries. Due to problematic -rpath-link the
linker may try to use host libraries if they are present and are arch
compatible.

Signed-off-by: Maciej Borzecki <maciej.borzecki@open-rnd.pl>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>