font-variant-alternates list support and case-insensitivity

[mdubet]

fd6f66d

font-variant-alternates list support and case-insensitivity
https://bugs.webkit.org/show_bug.cgi?id=246811
rdar://101638181

https://www.w3.org/TR/css-fonts-4/#font-variant-alternates-prop

CSS "character-variant" and "styleset" support a list of
feature names in CSS. Before this patch, only a single feature name was supported.

This patch also contains a change to make font family name matching
case insensitive for "@font-feature-values" at-rule.

Reviewed by Darin Adler.

* LayoutTests/TestExpectations:

The alternates-order.html layout test contains 9 specific tests related to font variant.
This patch fixes the remaining 2 out of 9 which were failing:
  - one because of the case-sensitivity in font name matching.
  - another because of the missing support for list value.

* LayoutTests/platform/gtk/TestExpectations:
* Source/WTF/wtf/text/WTFString.cpp:
(WTF::makeStringByJoining):
* Source/WTF/wtf/text/WTFString.h:
* Source/WebCore/css/CSSFontSelector.cpp:
(WebCore::CSSFontSelector::addFontFeatureValuesRule):
(WebCore::CSSFontSelector::lookupFontFeatureValues):
* Source/WebCore/css/CSSFontSelector.h:
* Source/WebCore/css/parser/CSSPropertyParser.cpp:
(WebCore::consumeFontVariantAlternates):
* Source/WebCore/platform/text/TextFlags.cpp:
(WebCore::operator<<):
(WebCore::computeFeatureSettingsFromVariants):
* Source/WebCore/platform/text/TextFlags.h:
* Tools/TestWebKitAPI/Tests/WTF/WTFString.cpp:
(TestWebKitAPI::TEST):

Canonical link: https://commits.webkit.org/256702@main

4f85275

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	💥 🛠 🧪 win
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-debug	✅ 🛠 gtk	✅ 🛠 wincairo
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🛠 mac-AS-debug	❌ 🧪 gtk-wk2
	✅ 🧪 api-ios	✅ 🧪 api-mac	✅ 🧪 api-gtk
✅ 🛠 🧪 jsc	✅ 🛠 tv	✅ 🧪 mac-wk1	✅ 🛠 jsc-armv7
	✅ 🛠 tv-sim	✅ 🧪 mac-wk2	✅ 🧪 jsc-armv7-tests
🛠 🧪 merge	✅ 🛠 watch	✅ 🧪 mac-AS-debug-wk2	✅ 🛠 jsc-mips
✅ 🛠 🧪 unsafe-merge	✅ 🛠 watch-sim	✅ 🧪 mac-wk2-stress	✅ 🧪 jsc-mips-tests

[webkit-early-warning-system]

EWS run on previous version of this PR (hash 185980c)

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 🧪 win
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-debug	✅ 🛠 gtk	✅ 🛠 wincairo
✅ 🧪 webkitperl	🧪 ios-wk2	✅ 🛠 mac-AS-debug	❌ 🧪 gtk-wk2
	🧪 api-ios	✅ 🧪 api-mac	✅ 🧪 api-gtk
✅ 🛠 🧪 jsc	✅ 🛠 tv	🧪 mac-wk1	✅ 🛠 jsc-armv7
	✅ 🛠 tv-sim	✅ 🧪 mac-wk2	✅ 🧪 jsc-armv7-tests
	✅ 🛠 watch	🧪 mac-AS-debug-wk2	✅ 🛠 jsc-mips
	✅ 🛠 watch-sim	✅ 🧪 mac-wk2-stress	✅ 🧪 jsc-mips-tests

[webkit-early-warning-system]

EWS run on previous version of this PR (hash c78a033)

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 🧪 win
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-debug	✅ 🛠 gtk	✅ 🛠 wincairo
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🛠 mac-AS-debug	✅ 🧪 gtk-wk2
	✅ 🧪 api-ios	✅ 🧪 api-mac	✅ 🧪 api-gtk
✅ 🛠 🧪 jsc	✅ 🛠 tv	✅ 🧪 mac-wk1	✅ 🛠 jsc-armv7
	✅ 🛠 tv-sim	✅ 🧪 mac-wk2	✅ 🧪 jsc-armv7-tests
	✅ 🛠 watch	✅ 🧪 mac-AS-debug-wk2	✅ 🛠 jsc-mips
	💥 🛠 watch-sim	✅ 🧪 mac-wk2-stress	✅ 🧪 jsc-mips-tests

[webkit-early-warning-system]

EWS run on current version of this PR (hash 4f85275)

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	💥 🛠 🧪 win
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-debug	✅ 🛠 gtk	✅ 🛠 wincairo
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🛠 mac-AS-debug	❌ 🧪 gtk-wk2
	✅ 🧪 api-ios	✅ 🧪 api-mac	✅ 🧪 api-gtk
✅ 🛠 🧪 jsc	✅ 🛠 tv	✅ 🧪 mac-wk1	✅ 🛠 jsc-armv7
	✅ 🛠 tv-sim	✅ 🧪 mac-wk2	✅ 🧪 jsc-armv7-tests
🛠 🧪 merge	✅ 🛠 watch	✅ 🧪 mac-AS-debug-wk2	✅ 🛠 jsc-mips
✅ 🛠 🧪 unsafe-merge	✅ 🛠 watch-sim	✅ 🧪 mac-wk2-stress	✅ 🧪 jsc-mips-tests

[webkit-commit-queue]

Committed 256702@main (fd6f66d): https://commits.webkit.org/256702@main

Reviewed commits have been landed. Closing PR #6299 and removing active labels.