Fix map for Julia v0.7 (#296)

* Fix `map` for Julia v0.7

This works around a redefinition of `map` for all `AbstractArray` that occurs on v0.7 but not v0.6.

This newly-missed optimization opportunities are probably pretty rare in practice.

* Wrong way

* Capture more `map`s in v0.7

Author: andyferris

src/mapreduce.jl

@@ -6,8 +6,14 @@
 
 # The following type signature for map() matches any list of AbstractArrays,
 # provided at least one is a static array.
-@inline function map(f, as::Union{SA,AbstractArray}...) where {SA<:StaticArray}
-    _map(f, same_size(as...), as...)
+if VERSION < v"0.7.0-"
+    @inline function map(f, as::Union{SA,AbstractArray}...) where {SA<:StaticArray}
+        _map(f, same_size(as...), as...)
+    end
+else
+    @inline function map(f, a1::StaticArray, as::AbstractArray...)
+        _map(f, same_size(a1, as...), a1, as...)
+    end
 end
 
 @generated function _map(f, ::Size{S}, a::AbstractArray...) where {S}