dillon1000/react

AnalyzeFunction: ref values take priority over other mutations

Small tweak necessary for the subsequent PRs, refs and ref values take 
precedence over other mutations when computing the effect type of context 
variables. We always want to record ref access within a function as capture 
(since we have later validation) rather than a mutation. For now this has no 
impact, either order records a Capture. But it allows later diffs to make 
non-ref cases have other effects.