add length type parameter to StepRangeLen and LinRange (#41619)

Allows creating these ranges for any type of integer lengths.

Also need to be careful about using additive identity instead of
multiplicative, and be even more consistent now about types in a
few places.

Fixes #41517

Author: vtjnash

base/broadcast.jl

@@ -1121,19 +1121,20 @@ end
 
 ## scalar-range broadcast operations ##
 # DefaultArrayStyle and \ are not available at the time of range.jl
-broadcasted(::DefaultArrayStyle{1}, ::typeof(+), r::OrdinalRange) = r
-broadcasted(::DefaultArrayStyle{1}, ::typeof(+), r::StepRangeLen) = r
-broadcasted(::DefaultArrayStyle{1}, ::typeof(+), r::LinRange) = r
+broadcasted(::DefaultArrayStyle{1}, ::typeof(+), r::AbstractRange) = r
 
-broadcasted(::DefaultArrayStyle{1}, ::typeof(-), r::OrdinalRange) = range(-first(r), step=-step(r), length=length(r))
+broadcasted(::DefaultArrayStyle{1}, ::typeof(-), r::AbstractRange) = range(-first(r), step=-step(r), length=length(r))
+broadcasted(::DefaultArrayStyle{1}, ::typeof(-), r::OrdinalRange) = range(-first(r), -last(r), step=-step(r))
 broadcasted(::DefaultArrayStyle{1}, ::typeof(-), r::StepRangeLen) = StepRangeLen(-r.ref, -r.step, length(r), r.offset)
 broadcasted(::DefaultArrayStyle{1}, ::typeof(-), r::LinRange) = LinRange(-r.start, -r.stop, length(r))
 
-broadcasted(::DefaultArrayStyle{1}, ::typeof(+), x::Real, r::AbstractUnitRange) = range(x + first(r), length=length(r))
-broadcasted(::DefaultArrayStyle{1}, ::typeof(+), r::AbstractUnitRange, x::Real) = range(first(r) + x, length=length(r))
 # For #18336 we need to prevent promotion of the step type:
 broadcasted(::DefaultArrayStyle{1}, ::typeof(+), r::AbstractRange, x::Number) = range(first(r) + x, step=step(r), length=length(r))
 broadcasted(::DefaultArrayStyle{1}, ::typeof(+), x::Number, r::AbstractRange) = range(x + first(r), step=step(r), length=length(r))
+broadcasted(::DefaultArrayStyle{1}, ::typeof(+), r::OrdinalRange, x::Real) = range(first(r) + x, last(r) + x, step=step(r))
+broadcasted(::DefaultArrayStyle{1}, ::typeof(+), x::Real, r::Real) = range(x + first(r), x + last(r), step=step(r))
+broadcasted(::DefaultArrayStyle{1}, ::typeof(+), r::AbstractUnitRange, x::Real) = range(first(r) + x, last(r) + x)
+broadcasted(::DefaultArrayStyle{1}, ::typeof(+), x::Real, r::AbstractUnitRange) = range(x + first(r), x + last(r))
 broadcasted(::DefaultArrayStyle{1}, ::typeof(+), r::StepRangeLen{T}, x::Number) where T =
     StepRangeLen{typeof(T(r.ref)+x)}(r.ref + x, r.step, length(r), r.offset)
 broadcasted(::DefaultArrayStyle{1}, ::typeof(+), x::Number, r::StepRangeLen{T}) where T =
@@ -1142,9 +1143,11 @@ broadcasted(::DefaultArrayStyle{1}, ::typeof(+), r::LinRange, x::Number) = LinRa
 broadcasted(::DefaultArrayStyle{1}, ::typeof(+), x::Number, r::LinRange) = LinRange(x + r.start, x + r.stop, length(r))
 broadcasted(::DefaultArrayStyle{1}, ::typeof(+), r1::AbstractRange, r2::AbstractRange) = r1 + r2
 
-broadcasted(::DefaultArrayStyle{1}, ::typeof(-), r::AbstractUnitRange, x::Number) = range(first(r)-x, length=length(r))
-broadcasted(::DefaultArrayStyle{1}, ::typeof(-), r::AbstractRange, x::Number) = range(first(r)-x, step=step(r), length=length(r))
-broadcasted(::DefaultArrayStyle{1}, ::typeof(-), x::Number, r::AbstractRange) = range(x-first(r), step=-step(r), length=length(r))
+broadcasted(::DefaultArrayStyle{1}, ::typeof(-), r::AbstractRange, x::Number) = range(first(r) - x, step=step(r), length=length(r))
+broadcasted(::DefaultArrayStyle{1}, ::typeof(-), x::Number, r::AbstractRange) = range(x - first(r), step=-step(r), length=length(r))
+broadcasted(::DefaultArrayStyle{1}, ::typeof(-), r::OrdinalRange, x::Real) = range(first(r) - x, last(r) - x, step=step(r))
+broadcasted(::DefaultArrayStyle{1}, ::typeof(-), x::Real, r::OrdinalRange) = range(x - first(r), x - last(r), step=-step(r))
+broadcasted(::DefaultArrayStyle{1}, ::typeof(-), r::AbstractUnitRange, x::Real) = range(first(r) - x, last(r) - x)
 broadcasted(::DefaultArrayStyle{1}, ::typeof(-), r::StepRangeLen{T}, x::Number) where T =
     StepRangeLen{typeof(T(r.ref)-x)}(r.ref - x, r.step, length(r), r.offset)
 broadcasted(::DefaultArrayStyle{1}, ::typeof(-), x::Number, r::StepRangeLen{T}) where T =