[llvm] [ADT][ProfileData] Introduce SortedVectorMap and switch CallTargetMap to it (PR #215733)

[Ellis Hoag via llvm-commits]

ellishg wrote:

Should we add a paragraph to our programmers manual for `SortedVectorMap`?

https://llvm.org/docs/ProgrammersManual.html#map-like-containers-std-map-densemap-etc

https://github.com/llvm/llvm-project/pull/215733