define broadcast! earlier (fixes JuliaLang#18462)

Author: stevengj

base/broadcast.jl

@@ -5,8 +5,8 @@ module Broadcast
 using Base.Cartesian
 using Base: promote_eltype_op, _default_eltype, linearindices, tail, OneTo, to_shape,
             _msk_end, unsafe_bitgetindex, bitcache_chunks, bitcache_size, dumpbitcache
-import Base: broadcast
-export broadcast!, bitbroadcast, dotview
+import Base: broadcast, broadcast!
+export bitbroadcast, dotview
 export broadcast_getindex, broadcast_setindex!
 
 ## Broadcasting utilities ##
@@ -18,7 +18,6 @@ export broadcast_getindex, broadcast_setindex!
 
 # special cases for "X .= ..." (broadcast!) assignments
 broadcast!(::typeof(identity), X::AbstractArray, x::Number) = fill!(X, x)
-broadcast!(f, X::AbstractArray) = fill!(X, f())
 broadcast!(f, X::AbstractArray, x::Number...) = fill!(X, f(x...))
 function broadcast!{T,S,N}(::typeof(identity), x::AbstractArray{T,N}, y::AbstractArray{S,N})
     check_broadcast_shape(broadcast_indices(x), broadcast_indices(y))

base/sysimg.jl

@@ -84,6 +84,7 @@ Symbol(x...) = Symbol(string(x...))
 # specific array types etc.
 #  --Here, just define fallback routines for broadcasting with no arguments
 broadcast(f) = f()
+broadcast!(f, X::AbstractArray) = fill!(X, f())
 
 # array structures
 include("array.jl")