git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@226367
91177308-0d34-0410-b5e6-
96231b3b80d8
IntervalMap is a compact map for small keys and values. It maps key intervals
instead of single keys, and it will automatically coalesce adjacent intervals.
-When then map only contains a few intervals, they are stored in the map object
+When the map only contains a few intervals, they are stored in the map object
itself to avoid allocations.
The IntervalMap iterators are quite big, so they should not be passed around as