Instead of computing the bit input flags at compile-time and inling
the final bit flag number, we will use the `InputFlags` enum directly.
This is a little more code in the compiler side, but will allow us to
have better debuggable development code, and also prevents problems
where runtime flag bitmasks differ from the compiler flag bitmasks.
This is in practice a noop for optimized applications as the enum values
would be inlined anyway. This matches existing compiler emit for e.g.
change detection strategy, or view encapsulation enums.
PR Close#53571