round(Int, π) throws an error, for example.

Description

Function selectors can be used to initialize constants while error and event selectors (recently introduced in #12921) are rejected as non-constant. I think that all of them should work the same way in that regard.

Steps to Reproduce

contract C {
    event Ev();
    error Er();
    function f() external {}

    bytes4 constant functionSelector = this.f.se

When declaring a type as private to a package, but then using that value as the default value poncy crashes (SIGSEGV) within llvm with the following message:

• PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.

Code to reproduce the error

// inside the "useful" package

primitive _PrivateDefault

actor Useful[

.> names #7pjlvdu42gmfvfntja265dmi08afk08l54kpsuu55l9hq4l32fco2jlrm8mf2jbn61esfsi972b6e66d9on4

  😶

  I couldn't find anything by that name.

.> view #7pjlvdu42gmfvfntja265dm

  #7pjlvdu42g : '{g} t -> Doc
  #7pjlvdu42g a = Special (EvalInline (term a))

I'd expect it to say something like:

I found that hash in your codebase, but it doesn't have any names.
Try `view 

Motivation

The Git class currently doesn't support submodules which prevents for example using submodules in Quark repos.

Description of Proposed Feature

Add a submodule method to Git and add submodule recursion to the Quark install step, eg adding the --recurse-submodules git flag to the clone command. This will download an