feat: add sign dispatches (#727)

Author: avik-pal

src/TracedRNumber.jl

@@ -242,6 +242,7 @@ for (jlop, hloop) in (
     (:(Base.asinh), :asinh),
     (:(Base.atan), :atan),
     (:(Base.atanh), :atanh),
+    (:(Base.sign), :sign),
 )
     @eval $(jlop)(@nospecialize(lhs::TracedRNumber)) = Ops.$(hloop)(lhs)
 end

test/basic.jl

@@ -561,6 +561,12 @@ end
     end
 end
 
+@testset "sign" begin
+    x = collect(Float64, 0:0.01:1) .- 0.5
+    x_ra = Reactant.to_rarray(x)
+    @test Array(@jit(sign.(x_ra))) ≈ sign.(x)
+end
+
 @testset "aos_to_soa" begin
     using ArrayInterface