If I read correctly some code in base/broadcast.jl is never executed now.

To be specific:

```
# Indices utilities
@inline combine_axes(A, B...) = broadcast_shape(axes(A), combine_axes(B...))
combine_axes(A) = axes(A)
broadcast_shape(shape::Tuple) = shape
broadcast_shape(shape::Tuple, shape1::Tuple, shapes::Tuple...) = broadcast_shape(_bcs(shape, shape1), shapes...)
_bcs(::Tuple{}, ::Tuple{}) = ()
_bcs(::Tuple{}, newshape::Tuple) = (newshape[1], _bcs((), tail(newshape))...) # FIX: =newshape ?
_bcs(shape::Tuple, ::Tuple{}) = (shape[1], _bcs(tail(shape), ())...) # FIX: =shape?
function _bcs(shape::Tuple, newshape::Tuple)
return (_bcs1(shape[1], newshape[1]), _bcs(tail(shape), tail(newshape))...)
end
_bcs1(a::Integer, b::Integer) = a == 1 ? b : (b == 1 ? a : (a == b ? a : throw(DimensionMismatch("arrays could not be broadcast to a common size")))) # never reached?
_bcs1(a::Integer, b) = a == 1 ? b : (first(b) == 1 && last(b) == a ? b : throw(DimensionMismatch("arrays could not be broadcast to a common size")))# never reached?
_bcs1(a, b::Integer) = _bcs1(b, a)# never reached?
_bcs1(a, b) = _bcsm(b, a) ? axistype(b, a) : (_bcsm(a, b) ? axistype(a, b) : throw(DimensionMismatch("arrays could not be broadcast to a common size")))
_bcsm(a, b) = a == b || length(b) == 1
_bcsm(a, b::Number) = b == 1# never reached?
_bcsm(a::Number, b::Number) = a == b || b == 1# never reached?
axistype(a::T, b::T) where T = a
axistype(a, b) = UnitRange{Int}(a)
```

is as good as

```
# Indices utilities
@inline combine_axes(A, B...) = broadcast_shape(axes(A), combine_axes(B...))
combine_axes(A) = axes(A)
broadcast_shape(shape::Tuple) = shape
broadcast_shape(shape::Tuple, shape1::Tuple, shapes::Tuple...) = broadcast_shape(_bcs(shape, shape1), shapes...)
_bcs(::Tuple{}, ::Tuple{}) = ()
_bcs(::Tuple{}, newshape::Tuple) = newshape
_bcs(shape::Tuple, ::Tuple{}) = shape
function _bcs(shape::Tuple, newshape::Tuple)
return (_bcs1(shape[1], newshape[1]), _bcs(tail(shape), tail(newshape))...)
end
_bcs1(a, b) = _bcsm(b, a) ? axistype(b, a) : (_bcsm(a, b) ? axistype(a, b) : throw(DimensionMismatch("arrays could not be broadcast to a common size")))
_bcsm(a, b) = a == b || length(b) == 1
axistype(a::T, b::T) where T = a
axistype(a, b) = UnitRange{Int}(a)
```

Am I missing something?