[ast-differ] sort diffs before output
[ast-differ] sort diffs before output

Summary: Currently, joining diffs can be error-prone because if the resulting diff is not in order by location, the output is unpredictable. This change fixes that by sorting the list of changes before outputting the final diff.

Reviewed By: nmote

Differential Revision: D12954360

fbshipit-source-id: 10d0b9449bb0551eb4b71e37e070e501e5a791b8

AgentME/flow,popham/flow,popham/flow,samwgoldman/flow,mroch/flow,mroch/flow,samwgoldman/flow,AgentME/flow,popham/flow,samwgoldman/flow,gabelevi/flow,samwgoldman/flow,facebook/flow,gabelevi/flow,facebook/flow,popham/flow,samwgoldman/flow,popham/flow,AgentME/flow,facebook/flow,facebook/flow,mroch/flow,facebook/flow,samwgoldman/flow,samwgoldman/flow,popham/flow,mroch/flow,gabelevi/flow,AgentME/flow,mroch/flow,popham/flow,gabelevi/flow,facebook/flow,mroch/flow,gabelevi/flow,gabelevi/flow,mroch/flow,AgentME/flow,gabelevi/flow,facebook/flow