Function LLVMBuildMemSet 

#[unsafe(no_mangle)]
pub extern "C" fn LLVMBuildMemSet(
    B: LLVMBuilderRef,
    Ptr: LLVMValueRef,
    Val: LLVMValueRef,
    Len: LLVMValueRef,
    Align: c_uint,
) -> LLVMValueRef