This reverts commit65429b9af6. Broke several projects, see https://reviews.llvm.org/D144509#4347562 onwards. Also reverts follow-up commit "[OpenMP] Compile assembly files as ASM, not C" This reverts commit4072c8aee4. Also reverts fix attempt "[cmake] Set CMP0091 to fix Windows builds after the cmake_minimum_required bump" This reverts commit7d47dac5f8.