* refactor `convertFuncOpToLLVMFuncOp` to accept a `FunctionOpInterface` instead of func::FuncOp * move `convertFuncOpToLLVMFuncOp` to corresponding public header, making it available for downstream project.
* refactor `convertFuncOpToLLVMFuncOp` to accept a `FunctionOpInterface` instead of func::FuncOp * move `convertFuncOpToLLVMFuncOp` to corresponding public header, making it available for downstream project.