IRShow: pass idx::Int to line_info_postprinter

[aviatesk]

Motivated by: JuliaDebug/Cthulhu.jl#225

[aviatesk]

This is really not a bugfix, but I want to backport this change to v1.7 if possible -- it would ease the development cost for Cthulhu and similar code tools because we can cut off the compatibility efforts.

[simeonschaub]

The index should already be passed inside the IOContext (see #41828), which I did to avoid any potential breakage. Can JuliaDebug/Cthulhu.jl#225 just use that?

[aviatesk]

yeah, it works. Thanks for your pointer !

Well, I feel it's a bit strange that we pass used as argument while wrapping idx in IOContext. We may want to pack used into IOContext as well ?

But yeah, this refactor shouldn't confuse the v1.7 release, and I think it's better to leave it for the future for now ?

[simeonschaub]

Well, I feel it's a bit strange that we pass used as argument while wrapping idx in IOContext. We may want to pack used into IOContext as well ?

I agree it feels a bit inconsistent, but I am not sure changing that is really worth it.