Attributes for jl_typeof (#2406)

* attributes for jl_typeof

* add dummy-test for jl_typeof

* move test to runtime_calls.jl

Author: MasonProtter

src/llvm/attributes.jl

@@ -1,4 +1,5 @@
 const nofreefns = Set{String}((
+    "jl_typeof",
     "julia.gc_loaded",
     "jl_egal__unboxed", "ijl_egal__unboxed",
     "jl_restore_excstack",
@@ -158,6 +159,7 @@ const nofreefns = Set{String}((
 ))
 
 const inactivefns = Set{String}((
+    "jl_typeof",
     "jl_egal__unboxed", "ijl_egal__unboxed",
     "ClientGetDevice",
     "BufferOnCPU",

test/runtests.jl

@@ -76,6 +76,7 @@ include("typetree.jl")
 include("passes.jl")
 include("optimize.jl")
 include("make_zero.jl")
+include("runtime_calls.jl")
 
 include("rules.jl")
 include("rrules.jl")

test/runtime_calls.jl

@@ -0,0 +1,8 @@
+@testset "jl_typeof" begin
+    # https://github.com/EnzymeAD/Enzyme.jl/issues/2405
+    function foo(x)
+        @ccall jl_typeof(Ref(x)::Ref{Float64})::Nothing
+        x + 1
+    end
+    @test autodiff(Reverse, foo, Active(1.0))[1][1] == 1.0
+end