Add primitive integration with JuliaLowering

[aviatesk]

Add primitive integration with JuliaLowering

This implements a very basic integration with JL.

You can retrieve inferred trees in the following way:

julia> using JET, JuliaSyntax

julia> result = @report_call sum("julia")
═════ 2 possible errors found ═════
┌ sum(a::String) @ Base ./reduce.jl:553
│┌ sum(a::String; kw::@Kwargs{}) @ Base ./reduce.jl:553
││┌ sum(f::typeof(identity), a::String) @ Base ./reduce.jl:524
│││┌ sum(f::typeof(identity), a::String; kw::@Kwargs{}) @ Base ./reduce.jl:524
││││┌ mapreduce(f::typeof(identity), op::typeof(Base.add_sum), itr::String) @ Base ./reduce.jl:299
│││││┌ mapreduce(f::typeof(identity), op::typeof(Base.add_sum), itr::String; kw::@Kwargs{}) @ Base ./reduce.jl:299
││││││┌ mapfoldl(f::typeof(identity), op::typeof(Base.add_sum), itr::String) @ Base ./reduce.jl:167
│││││││┌ mapfoldl(f::typeof(identity), op::typeof(Base.add_sum), itr::String; init::Base._InitialValue) @ Base ./reduce.jl:167
││││││││┌ mapfoldl_impl(f::typeof(identity), op::typeof(Base.add_sum), nt::Base._InitialValue, itr::String) @ Base ./:36
│││││││││┌ foldl_impl(op::Base.BottomRF{typeof(Base.add_sum)}, nt::Base._InitialValue, itr::String) @ Base ./:40
││││││││││┌ _foldl_impl(op::Base.BottomRF{typeof(Base.add_sum)}, init::Base._InitialValue, itr::String) @ Base ./reduce.jl:54
│││││││││││┌ (::Base.BottomRF{typeof(Base.add_sum)})(acc::Char, x::Char) @ Base ./:78
││││││││││││┌ add_sum(x::Char, y::Char) @ Base ./:16
│││││││││││││ no matching method found `+(::Char, ::Char)`: (x::Char + y::Char)
││││││││││││└────────────────────
│││││││││┌ foldl_impl(op::Base.BottomRF{typeof(Base.add_sum)}, nt::Base._InitialValue, itr::String) @ Base ./:41
││││││││││┌ reduce_empty_iter(op::Base.BottomRF{typeof(Base.add_sum)}, itr::String) @ Base ./:372
│││││││││││┌ reduce_empty_iter(op::Base.BottomRF{typeof(Base.add_sum)}, itr::String, ::Base.HasEltype) @ Base ./:373
││││││││││││┌ reduce_empty(op::Base.BottomRF{typeof(Base.add_sum)}, ::Type{Char}) @ Base ./:349
│││││││││││││┌ reduce_empty(::typeof(Base.add_sum), ::Type{Char}) @ Base ./:342
││││││││││││││┌ reduce_empty(::typeof(+), ::Type{Char}) @ Base ./:335
│││││││││││││││ no matching method found `zero(::Type{Char})`: zero(T::Type{Char})
││││││││││││││└────────────────────

julia> inferred = JET.get_trees(result, :add_sum)
1-element Vector{JuliaLowering.SyntaxTree}:
 (method core.nothing %₈ (code_info (block Base.+ (call %₁ slot₂/x slot₃/y) (return %₂))))

julia> JuliaSyntax.sourcetext(inferred[1])
"add_sum(x, y) = x + y"

There are several things to note:

• Please run Pkg.instantiate() after checking out to this branch to install JL
• I couldn't think of a good way to integrate this system with the existing cache system, so for now I disabled all the global cache for now on this branch.
• In cases where retrieval of the JL.SyntaxTree corresponding to the target CodeInfo for inference fails, no inferred tree will exist. Currently, retrieval likely doesn't work well for keyword methods and methods with default arguments eit