[llvm] [ORC-RT] Initial check-in for a new, top-level ORC runtime project. (PR #113499)

[Lang Hames via llvm-commits]

lhames wrote:

Updated to include regression and unit tests. The new ORC runtime should now build on Darwin or Linux as either a bootstrap build (cmake pointed at `llvm-project/llvm`) or a standalone build (cmake pointed at `llvm-project/runtimes`). When building standalone clients should pass `-DLLVM_BINARY_DIR=/path/to/llvm-obj-dir`, `-DORC_RT_LLVM_TOOLS_DIR=/path/to/llvm-tools-dir`, or individually pass paths to the test tools via `ORC_RT_FILECHECK_EXECUTABLE` and `ORC_RT_NOT_EXECUTABLE`.

https://github.com/llvm/llvm-project/pull/113499