v1.12: revisit more efficient and more context-aware `LineInfoNode`

[aviatesk]

JuliaInterpreter.jl/src/utils.jl

Lines 280 to 285 in ebc743a

	function linetable(arg, i::Integer; macro_caller::Bool=false)::Union{Expr,LineTypes}
	lt = linetable(arg)
	@static if VERSION ≥ v"1.12.0-DEV.173"
	# TODO: decode the linetable at this frame efficiently by reimplementing this here
	# TODO: get the contextual name from the parent, rather than returning "n/a" (which breaks Cthulhu)
	return Base.IRShow.buildLineInfoNode(lt, :var"n/a", i)[1] # ignore all inlining / macro expansion / etc :(

I don't understand this commit -- do we now store some macro expansion context within debuginfo?

Originally posted by @aviatesk in #606 (comment)