Implement jl_call convention for 1.9

[vchuravy]

Test threw exception
  Expression: 0.5 ≈ (Enzyme.autodiff(dyn_mwe, Active, Active(1.0), Const((1, 2))))[1]
  AssertionError: ("jl_call calling convention not implemented yet",   %6 = call noalias nonnull {} addrspace(10)* ({} addrspace(10)* ({} addrspace(10)*, {} addrspace(10)**, i32)*, {} addrspace(10)*, ...) @julia.call({} addrspace(10)* ({} addrspace(10)*, {} addrspace(10)**, i32)* noundef nonnull @ijl_new_structv, {} addrspace(10)* nonnull %5) #18, !dbg !21)
  Stacktrace:
    [1] jlcall_augfwd(B::Ptr{LLVM.API.LLVMOpaqueBuilder}, OrigCI::Ptr{LLVM.API.LLVMOpaqueValue}, gutils::Ptr{Nothing}, normalR::Ptr{Ptr{LLVM.API.LLVMOpaqueValue}}, shadowR::Ptr{Ptr{LLVM.API.LLVMOpaqueValue}}, tapeR::Ptr{Ptr{LLVM.API.LLVMOpaqueValue}})
      @ Enzyme.Compiler ~/work/Enzyme.jl/Enzyme.jl/src/compiler.jl:1305

[wsmoses]

I can do that right now, but the actual issue isn't this specifically, but that 1.9 creates a type unstable newstructv call, which we dont handle in any version. This isn't the case for lower versions.

[wsmoses]

ERROR: LoadError: Enzyme: Not yet implemented augmented forward for jl_new_struct
Stacktrace:
 [1] Val
   @ ./essentials.jl:793
 [2] Val
   @ ./essentials.jl:795
 [3] dyn_mwe
   @ ~/git/Enzyme.jl/dval.jl:5
 [4] dyn_mwe
   @ ~/git/Enzyme.jl/dval.jl:0
Stacktrace:
 [1] top-level scope
   @ show.jl:1128
in expression starting at /home/wmoses/git/Enzyme.jl/dval.jl:7