InitAll*** functions are used by opt-style tools to init all MLIR dialects/passes/extensions. Currently they are implemeted as inline functions and include essentially the entire MLIR header tree. Each file which includes this header (~10 currently) can take 10+ sec and multiple GB of ram to compile (tested with clang-19), which limits amount of parallel compiler jobs which can be run. Also, flang just includes this file into one of its headers.
I propose to move actual implementation into static library, so it’s compiled only once.
