Adapt to CC.finish!(...) signature changes

[serenity4]

The change in JuliaLang/julia#57248 caused the CC.finish!(::CthulhuInterpreter, ...) override to be ignored, skipping the creation of the OptimizedSource.

The following testset fails:

Cthulhu.jl/test/test_Cthulhu.jl

Lines 381 to 412 in a8fcae8

	@testset "ReturnTypeCallInfo" begin
	only_ints(::Integer) = 1
	callsites = find_callsites_by_ftt(; optimize=false) do
	t1 = Base._return_type(only_ints, Tuple{Int}) # successful `return_type`
	t2 = Base._return_type(only_ints, Tuple{Float64}) # failed `return_type`
	t1, t2
	end
	@test length(callsites) == 2
	callinfo1 = callsites[1].info
	@test callinfo1 isa Cthulhu.ReturnTypeCallInfo
	@test callinfo1.vmi isa Cthulhu.MICallInfo
	io = IOBuffer()
	Cthulhu.show_callinfo(io, callinfo1)
	@test String(take!(io)) == "only_ints(::$Int)::$Int"
	io = IOBuffer()
	print(io, callsites[1])
	@test occursin("return_type < only_ints(::$Int)::$Int >", String(take!(io)))
	callinfo2 = callsites[2].info
	@test callinfo2 isa Cthulhu.ReturnTypeCallInfo
	@test callinfo2.vmi isa Cthulhu.FailedCallInfo
	io = IOBuffer()
	Cthulhu.show_callinfo(io, callinfo2)
	@test String(take!(io)) == "only_ints(::Float64)::Union{}"
	io = IOBuffer()
	print(io, callsites[2])
	@test occursin("return_type < only_ints(::Float64)::Union{} >", String(take!(io)))
	@test Cthulhu.get_effects(callinfo1) |> CC.is_foldable_nothrow
	@test Cthulhu.get_effects(callinfo2) |> CC.is_foldable_nothrow
	end

because the code now contains calls to getproperty:

julia> callsites = find_callsites_by_ftt(; optimize=false) do
                   t1 = CC._return_type(only_ints, Tuple{Int})     # successful `return_type`
                   t2 = CC._return_type(only_ints, Tuple{Float64}) # failed `return_type`
                   t1, t2
               end
4-element Vector{Cthulhu.Callsite}:
 %2 = runtime < getproperty(::Any,::Core.Const(:_return_type))::Any >
 %7 = runtime < Any(::Core.Const(Main.only_ints),::Core.Const(Tuple{Int64}))::… …
 %9 = runtime < getproperty(::Any,::Core.Const(:_return_type))::Any >
 %14 = runtime < Any(::Core.Const(Main.only_ints),::Core.Const(Tuple{Float64})) …

Not sure if we want to update the testset or have a rule to ignore getproperty calls, but in any case this can be merged to have nightly working.

[aviatesk]

Oops, I totally missed that PR #621 and created a new one.

[aviatesk]

Let me replace this with #621.