It seems modern compilers don't realize that all invocations of operator""_mst
can be evaluated at compile time, despite the constexpr keyword.
Since C++20, we can force them to evaluate at compile time, turning all the
miniscript type constants into actual compile-time constants.
It appears that MSVC does not support consteval operator"" when used inside
certain expressions. For the few places where this happens, define a
constant outside the operator call.
Co-Authored-By: Hennadii Stepanov <32963518+hebasto@users.noreply.github.com>