Function LLVMAddGlobalIFunc 

#[unsafe(no_mangle)]
pub extern "C" fn LLVMAddGlobalIFunc(
    M: LLVMModuleRef,
    Name: *const c_char,
    NameLen: size_t,
    Ty: LLVMTypeRef,
    AddrSpace: c_uint,
    Resolver: LLVMValueRef,
) -> LLVMValueRef