Compat.Unicode.normalize refers to wrong functions

[ExpandingMan]

julia> methods(Compat.Unicode.normalize)
# 2 methods for generic function "normalize":
normalize(v::AbstractArray{T,1} where T) in Base.LinAlg at linalg/generic.jl:1367
normalize(v::AbstractArray{T,1} where T, p::Real) in Base.LinAlg at linalg/generic.jl:1367

[stevengj]

Since this was renamed from normalize_string in the same PR that created the Unicode module (JuliaLang/julia#25021), the fix is simple: in the VERSION < v"0.7.0-DEV.2915" case, just add:

const normalize = normalize_string

and add normalize to the exports.