This commit reimplements the (normally) 45 degree (depends on
the widths) connection between to adjacent borders. Which is
needed to paint the 'caret' icon seen in a few buttons on GitHub.
The issue of overlapping pixels while painting this has also
been solved for the 45 degree case (the the most likely case,
the other cases only occur of mixed-with borders).
Jokes don't scale well, and if everyone adds their pet "funny" thing
to the project, we'll just look unserious and goofy.
To avoid that, and maintain a dignified style, let's just have a blanket
ban on jokes and "funny" things in user-facing parts of the system.
This change updates the parameter order of the is_less_than function
signature and calls to match accordingly with the spec
(https://tc39.es/ecma262/#sec-islessthan)
This commit adds some much nicer border painting, which now supports:
- Elliptical corners
- Blending between different border thicknesses, with rounded corners
- Anti-aliasing
There are some little TODOs left to tackle:
- Painting the corners with line styles other than solid
- Blending between colors on the corners (see comments)
The painting requires allocating a small bitmap, that only fits the
corners (so in most cases this is very small).
This bitmap is then cached so for all paints but the first there will
be no further allocations.
Previously we only threw an error if the enum was used as a function
argument. However, we are supposed to throw an error no matter the
context it is used in.
It's a common pattern on the web to draw a circle/ellipse by setting
the border-radius to 50%. Previously the painter would do a lot of
extra work painting and clipping each corner, this now detects that
case and replaces it with a single call to fill_ellipse().
This allows you to recurse into a named function that is stored in a
variable. For example, this would previously print "wrong" instead of
"right":
```js
function g() { console.log("wrong") }
f = function g(i) { if (i !== 1) g(1); else console.log("right"); }
f()
```
Previously it would pass in `is_arrow_function` as
`contains_direct_call_to_eval`, which broke strict mode propagation in
arrow functions. This makes test-js work without falling apart because
`this` is mysteriously undefined because of the use of arrow functions
inside classes, which are strict mode by default.
