We now lazily create an "arguments" array inside functions when code
tries to access it.
This doesn't follow the spec at all but still covers a lot of the
basic uses of arguments, i.e "arguments.length" and "arguments[n]"
Here's a reasonably faithful implementation of ECMAScript 2021 18.2.5.
Some corner cases are not covered, I've left them as FIXME's in the
included unit test.
Also I had to tweak JS::Value::to_i32() to always convert infinity to
zero, which is in accordance with ToInt32 AFAICT.
This patch adds six of the standard type arrays and tries to share as
much code as possible:
- Uint8Array
- Uint16Array
- Uint32Array
- Int8Array
- Int16Array
- Int32Array
This makes RegExpObject compile and store a Regex<ECMA262>, adds
all flag-related properties, and implements `RegExpPrototype.test()`
(complete with 'lastIndex' support) :^)
It should be noted that this only implements `test()' using the builtin
`exec()'.
Roughly 7% of test-js runtime was spent creating FlyStrings from string
literals. This patch frontloads that work and caches all the commonly
used names in LibJS on a CommonPropertyNames struct that hangs off VM.
