When we have a `calc` which is a mix of a dimension and a percentage, we
should use the percentage alone for the computed value if the dimension
component is 0 e.g. `calc(50% + 0px)` should use `50%` as it's computed
value.
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.
Without this, we'd happily parse `font-variant-caps: small-caps potato`
as just `small-caps` and ignore the fact that unused tokens were left
over.
This fix gets us some WPT subtest passes, and removes the need for a
bespoke parsing function for font-variant-caps.
If a calculation was simplified down to a single numeric node, then most
of the time we can instead return a regular StyleValue, for example
`calc(2px + 3px)` would be simplified down to a `5px` LengthStyleValue.
This means that parse_calculated_value() can't return a
CalculatedStyleValue directly, and its callers all have to handle
non-calculated values as well as calculated ones.
This simplification is reflected in the new test results. Serialization
is not yet correct in all cases but we're closer than we were. :^)
This allows us to disable test output, which performs expensive assert
tracking. This was making our imported tests run significantly slower
than tests run via `WPT.sh`.
Formatting the output ourselves also allows us to remove unnecessary
information from the test output.
This commit also rebaselines all existing imported WPT tests to follow
the new format.
