zeek
Optimizer does not track feature requirements for functions args passed as `any`
We currently use the attribute &requires-type-feature on function arguments
to notify the optimizer that use of the function introduces a feature
requirement on the arg type. The optimizer takes this information into account when
deciding whether to remove feature-dependent code.
This does not seem to work correctly when used with any parameters. We
currently have e.g., the following declaration
https://github.com/zeek/spicy/blob/ba586baeae7296eff9c3a3efc34532b545260b70/spicy/lib/spicy_rt.hlt#L42
The intention of the requirement is that for any concrete parser type passed as
an argument to this function the supports_filters feature needs to be active.
It however looks like the code performing the bookkeeping does not correctly
track the feature,
https://github.com/zeek/spicy/blob/ba586baeae7296eff9c3a3efc34532b545260b70/hilti/toolchain/src/compiler/optimizer.cc#L948-L976
That this example with supports_filters works at all at the moment seems to
be due to us enabling the feature due to requirements elsewhere.
Removing 1.4 milestone as it seems to be possible to address #1131 with touching this.