jump, branchif, etc don't invalidate locals in the JIT; they might in the interpreter because they can execute arbitrary code, but the JIT side exits before that happens.

This can happen with documentation updates and we don't want
those to trip on ZJIT tests.

Redact the whole name since names like "_bi342" aren't that helpful
anyways.

It's just a nicety (they fit fine as CUInt32) but this makes printing
look nicer in real execution and also in tests (helps with #15489).

Co-authored-by: Randy Stauner <randy@r4s6.net>

Fix https://github.com/Shopify/ruby/issues/874

No point doing the manual size unit conversion for add. Sorry, no new
tests since there is no way to generate a LoadField with a negative
offset from ruby code AFAICT. Careful with the `as` casts.

* ZJIT: Fold LoadField on frozen objects to constants

When accessing instance variables from frozen objects via attr_reader/
attr_accessor, fold the LoadField instruction to a constant at compile
time. This enables further optimizations like constant propagation.

- Add fold_getinstancevariable_frozen optimization in Function::optimize
- Check if receiver type has a known ruby_object() that is frozen
- Read the field value at compile time and replace with Const instruction
- Add 10 unit tests covering various value types (fixnum, string, symbol,
  nil, true/false) and negative cases (unfrozen, dynamic receiver)

* Run zjit-test-update

* Add a test that we don't fold non-BasicObject

* Small cleanups

---------

Co-authored-by: Max Bernstein <ruby@bernsteinbear.com>
Co-authored-by: Aaron Patterson <tenderlove@ruby-lang.org>