No more scalar operations on CuArrays.

[ali-ramadhan]

This PR fixes a recent regression in Model construction time due to broadcasting over an OffsetArray{CuArray} getting converted to a scalar operation. Constructing models should be fast again.

I've also completely disabled scalar operations on CuArrays so this shouldn't happen again.

cc @sandreza

Actually fixes #82

[glwagner]

👍

[glwagner]

Would also be useful to have a function (ie, parentdata) that returns a view over the parent

[codecov]

Codecov Report

Merging #264 into master will increase coverage by 0.41%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #264      +/-   ##
==========================================
+ Coverage   70.73%   71.14%   +0.41%     
==========================================
  Files          23       23              
  Lines         868      870       +2     
==========================================
+ Hits          614      619       +5     
+ Misses        254      251       -3

Impacted Files	Coverage Δ
src/Oceananigans.jl	71.42% <ø> (ø)	⬆️
src/models.jl	90.47% <100%> (ø)	⬆️
src/boundary_conditions.jl	78.78% <0%> (+11.04%)	⬆️

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[codecov]

Codecov Report

Merging #264 into master will increase coverage by 0.29%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #264      +/-   ##
==========================================
+ Coverage   70.73%   71.03%   +0.29%     
==========================================
  Files          23       23              
  Lines         868      870       +2     
==========================================
+ Hits          614      618       +4     
+ Misses        254      252       -2

Impacted Files	Coverage Δ
src/Oceananigans.jl	71.42% <ø> (ø)	⬆️
src/models.jl	90% <100%> (-0.48%)	⬇️
src/fields.jl	58.82% <100%> (+1.24%)	⬆️
src/planetary_constants.jl	9.67% <0%> (-3.23%)	⬇️
src/boundary_conditions.jl	78.78% <0%> (+11.04%)	⬆️

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[ali-ramadhan]

Would also be useful to have a function (ie, parentdata) that returns a view over the parent

Decided to go with underlying_data(::Field) as it's a clearer name than parent, and I think it's a little different from Base.parent, but I'm not opposed to overloading Base.parent.

[glwagner]

I suggested “parentdata” to match the semantics of OffsetArrays, but underlyingdata is ok with me.

[vchuravy]

x-ref: JuliaArrays/OffsetArrays.jl#57