Code review for ResolveBlockingInput


Based on: https://github.com/kframework/k/commit/8f11fa41cb21a8108db310113d11e4c8eabc39dc#commitcomment-5487975

@dwightguth: I tried to take your comments into consideration.  Please re-review them (the two commits at the end). 

However, I'm not sure about the merging I did.  I needed to merge in changes from master to get the DependsOn annotation you wrote, but rebase would give me conflicts I already had resolved for the unified-builtins2 branch, and merge apparently added the in-between commits to the pull request which does not seem right for a code review.

Could you please help me out here what would be the best practice?