Default to ismutable(array) = true

Author: tkf

src/ArrayInterface.jl

@@ -12,12 +12,9 @@ function ismutable end
 Query whether a type is mutable or not, see
 https://github.com/JuliaDiffEq/RecursiveArrayTools.jl/issues/19.
 """
-Base.@pure ismutable(x::DataType) = x.mutable
 ismutable(x) = ismutable(typeof(x))
 
-ismutable(::Type{<:Array}) = true
-ismutable(::Type{<:SparseMatrixCSC}) = true
-ismutable(::Type{<:SparseVector}) = true
+ismutable(::Type{<:AbstractArray}) = true
 ismutable(::Type{<:Number}) = false
 
 # Piracy