This entirely abolishes the "global scope object" in AVM2. I even had to redefine several global object functions to work with the bottom of the scope stack, which seems to be where ASC likes to stick the script scope.
* Implement `add`, with tests.
* Implement `add_i`.
There's no test, because for whatever reason, I can't figure out how to emit this from Animate CC 2020.
* avm2: Implement `bitand` with tests.
* Implement `bitnot` with tests.
* Implement `bitor` with tests.
* avm2: Implement `bitxor`
* avm2: Implement `declocal`, `declocal_i`, `decrement`, and `decrement_i`.
* tests: `swf_approx` tests should be allowed to print NaNs.
* avm2: Implement `divide`.
* avm2: Implement `inclocal`, `inclocal_i`, `increment`, and `increment_i`.
* avm2: Implement `lshift`.
* Implement `modulo`.
* avm2: Implement `multiply` and `multiply_i` (no tests for the latter)
* avm2: Implement `negate` and `negate_i` (no tests for the latter)
* avm2: Implement `rshift`
* avm2: Implement `subtract` and `subtract_i` (the latter without tests)
* avm2: Implement `urshift`.
Namespaces as values adds a bunch of extra special cases to the coercion and equality rules that don't really belong there. Namespace itself just returns it's URI as a string, so we can just make `NamespaceObject` do that and then treat it the same way we treat boxed primitives.
These include:
* Name resolution in `newobject`
* All runtime & late-bound multinames
* `Object.hasOwnProperty`
* `Object.propertyIsEnumerable`
* `Object.setPropertyIsEnumerable`
AVM2 is based on ES4, which as far as I'm aware, does not distinguish between "primitive values" and "objects". Thus, it is expedient to interpret any statement requiring something to be an Object to mean "not null or undefined".
Since we internally represent register values with primitive types, it is important that the VM always coerces to object before doing any other sort of type checking. Hence, something like `as_object` is unhelpful as it accidentally enforces a primitive/object distinction that ES4 attempted to remove.
The test is also far more in-depth than the `if_eq`/`if_ne` tests, which use the same set of vectors as the strict-equality tests from a while ago. Interestingly, this test passed on first run
Implementation is limited to generating exceptions on `null` or `undefined`. I'm not sure if primitive values don't exist in AVM2 or if this is supposed to box them like ES3, so I have decided to handle neither at this time.
The ECMA-262 documentation is awfully overwrought for something that boils down to "chop off the non-whole part, wrap to 32 bits, then reinterpret as signed". Bitwise operations are *hell* to describe mathematically, and such descriptions are even harder to understand.
For whatever reason, `pushbyte` appears to be processed as a *signed* byte, despite the clear wording of "*byte_value* is an unsigned byte" in avm2overview.pdf. I guess it's supposed to be manually converted and promoted in this manner.
Functions that need to assert Boolness without coercion should either:
1. Ensure their function declaration requires a Boolean. (We don't enforce type errors on ES4 typehints yet, but we should.)
2. Check the value type themselves and raise their own errors if necessary.
As it stands the only users of `as_bool` either needed to check the type themselves or use `coerce_to_bool`. Notably, `setPropertyIsEnumerable` doesn't appear to coerce *or* throw an error: it instead fails silently if you hand it a non-`Boolean` value.
For good measure, most of the other methods in `value` for retrieving pool primitives now also use `TranslationUnit` instead of `AbcFile`. This is the result of a handful of cascading changes throughout the project, and itself caused a few more.
CUB3D