Fix warnings

[benthevining]

• clang++: warning: argument unused during compilation: '-stdlib=libc++' [-Wunused-command-line-argument]
• MSVC
• warning: conversion from ‘uint128_t’ {aka ‘__int128 unsigned’} to ‘uint64_t’ {aka ‘long unsigned int’} may change value [-Wconversion]
• warning: expansion of date or time macro is not reproducible [-Wdate-time]