This now uses `if constexpr (...)` which is a lot more readable, and still compiles to almost no assembly instructions, as expected. Floating point casting assert when casting an integer that's too large to be represented exactly as a floating point (e.g. UINT64_MAX to double, since double have less than 64 bytes of mantissa), or when casting a double that's too large to be represented in a float.
Since these are just interpreted comments, there's 0 impact on actual code.
This removes all lines that match /* vim: set(.*)tw=80: */ with S&R -- there are
a few others scattered around which will be removed manually in a second part.