Remove BLAS.asum(x) rules

Author: YingboMa

src/rulesets/LinearAlgebra/blas.jl

@@ -67,20 +67,6 @@ end
 ##### `BLAS.asum`
 #####
 
-function frule(::typeof(BLAS.asum), x, _, Δx)
-    return BLAS.asum(x), sum(zip(x, Δx)) do xs
-        x, Δx = xs
-        return sign(x) * Δx
-    end
-end
-
-function rrule(::typeof(BLAS.asum), x)
-    function asum_pullback(ΔΩ)
-        return (NO_FIELDS, @thunk(ΔΩ * sign.(x)))
-    end
-    return BLAS.asum(x), asum_pullback
-end
-
 function rrule(::typeof(BLAS.asum), n, X, incx)
     Ω = BLAS.asum(n, X, incx)
     function asum_pullback(ΔΩ)