Vector35
Use constexpr arrays for metadata about IL instruction operands
This avoids constructing numerous unordered maps and vectors at library load time in every plug-in that uses the C++ API. Additionally, the arrays allow for more efficient look-ups.
In general I'm a huge fan of this PR. I appreciate all the static asserts which should help this code from breaking in the future. I don't see downsides to any of this. This seems like it should shave off some bytes on every IL instruction allocation which is a nice win too.
I was trying to see if anything could be made consteval to provide stronger guarantees of compile-time generation but I'm not sure about which parts could be converted or what the compiler support is for consteval.
In practice, what we care about is that the static variables are compile-time constants and not initialized at runtime. Being declared as static constexpr provides that guarantee. Adding consteval would be useful if what we care about is guaranteeing that a given function is only ever used at compile time. That's less important here since the functions are implementation details.