Llvm_analysis

`sig external verify_module : Llvm.llmodule -> string option = "llvm_verify_module" external verify_function : Llvm.llvalue -> bool = "llvm_verify_function" external assert_valid_module : Llvm.llmodule -> unit = "llvm_assert_valid_module" external assert_valid_function : Llvm.llvalue -> unit = "llvm_assert_valid_function" external view_function_cfg : Llvm.llvalue -> unit = "llvm_view_function_cfg" external view_function_cfg_only : Llvm.llvalue -> unit = "llvm_view_function_cfg_only" end`