Doing trigonometric calculations with floating point numbers can
introduce small inaccuracies. This meant that we would sometimes
incorrectly generate a 3d rather than 2d matrix for the resolved value
of `transform`.
Gains us 3 WPT tests.
Previously we would always use the window's viewport which was incorrect
if we were within an iframe.
This is likely applicable to all uses of
`Length::ResolutionContext::for_window`.
We now clamp the values returned from calc into the allowed range (where
we know it) and censor any `NaN`s to `0` both when we resolve and when
we serialize.
Gains us 76 WPT passes.
Previously, we would allow calc values such as `calc(min(1 2))`, which
would be simplified to `calc(3)` because we assumed that numbers not
separated by an operator represented a sum. We now validate that the
number of operators we see is as we would expect before collecting
these values into a sum node.
Previously we would never get a valid `consistent_type` as we were
trying to make the node types consistent with the initial empty type
which isn't possible.
Gains us 7 WPT tests.
Math functions like abs(), clamp(), round(), etc, can be used by
themselves in property values, without wrapping them in calc().
Before this change, we were neglecting to run calc simplification on the
generated calculation node trees. By doing that manually after parsing a
standalone math function, we score at least a couple hundred WPT points.
