jl_options no longer exported by libjulia.so

[dalekj]

In order to call some Julia code from MATLAB, I have a c program with Julia embedded which gets compiled as a MEX function. Because MATLAB (or JVM) do weird things with signals, I have to turn off Julia's signal handling by incorporating the following line in my c program.

jl_options.handle_signals = JL_OPTIONS_HANDLE_SIGNALS_OFF;

For Julia versions through v1.5.x, jl_options was exported by libjulia.so, supporting this. However, with the library split into libjulia.so and libjulia-internal.so that occurred in v1.6, jl_options is no longer exported by libjulia.so, although it is exported by libjulia-internal.so. If I link to both of the libraries, things work as expected, but it is my understanding that this is not the supported interface to embedding Julia; libjulia.so is the supported entry point for embedding Julia.

Could jl_options be added to the libjulia.so re-export list for future versions?
Or if there is a good reason not to provide access to jl_options, is there an alternative way to turn off Julia's signal handling?

[vtjnash]

Yes, we should export a pointer to jl_options, for external consumers

[JeffBezanson]

I have a fix for this in #41936; can separate and backport it.

[dalekj]

Thanks for fixing this.
@JeffBezanson is it possible to get the fix backported to 1.6.x since that is the new LTS?