WIP: Print evaluated LHS and RHS in comparison tests

This builds off the PR by @iainNZ https://github.com/JuliaLang/julia/pull/6106.

I am trying to avoid evaluating the RHS and LHS twice as noticed by Jeff in #6106. For some reason the tests for 7197 are failing in arrayops.jl. I also think that this is slowing down the tests since we need to assign the results from the LHS and RHS to something.

This is how I am debugging: https://github.com/sjkelly/JuliaPlayground/blob/master/test/test_output.jl

I will make a few comments and observations inline with the code. Metaprogramming is new to me, and I am still learning, but I think this feature in the test output would be helpful.