Fix conic-gradient edge cases

Quotes from the spec[1]:

> Infinities do not escape a top-level calculation;
they’re clamped to the minimum or maximum value allowed in the context,
as defined in § 10.12 Range Checking.

> NaN does not escape a top-level calculation;
 it’s censored into a zero value

This CL fixes the conic-gradient edge cases by clamping out the NaN and
+Inf/-Inf as per spec say[1].

[1]https://www.w3.org/TR/css-values-4/#calc-ieee

Bug: 403764637
Change-Id: I210c3cc1728457012ac8f31c84379bf29b4c69b0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6361617
Reviewed-by: Rune Lillesveen <futhark@chromium.org>
Reviewed-by: Fredrik Söderquist <fs@opera.com>
Commit-Queue: Rune Lillesveen <futhark@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1435310}