swift

e29e035a - [region-analysis] Add a pass that explicitly invalidates RegionAnalysis.

[region-analysis] Add a pass that explicitly invalidates RegionAnalysis. Over time I am going to be using RegionAnalysis for a series of passes that all use that same information since I am worried about RegionAnalysis computation time. With that being said, we want to make sure to eliminate the memory that RegionAnalysis uses once this series of passes have completed. What this commit does is create a pass that explicitly invalidates region analysis and explicitly places it in the pass pipeline after the series of passes. This will ensure that even if we add an additional pass, there is a strong "rattlesnake" signal to the new code author that the code needs to be placed before the region analysis invalidation and will prevent mistakes such as having to recompute the region analysis in that later pass or the later pass forgeting to invalidate the analysis.