Suspect differences between IE and Edge support

[foolip]

#23791 was a case where there was an IE version, but Edge was set to mirror, resulting in Edge 79. This is probably correct in some case, but there are probably more errors of this sort.

comm -23 <(npm run traverse -- -b edge -f mirror | sort) <(npm run traverse -- -b ie -f false -f null | sort) produces this list for review:

• api.BeforeUnloadEvent (Mark BeforeUnloadEvent supported in Edge 12 #23797)
• api.BeforeUnloadEvent.returnValue (Mark BeforeUnloadEvent supported in Edge 12 #23797)
• api.Document.releaseCapture
• api.IDBObjectStore.autoIncrement
• api.IDBObjectStore.openKeyCursor
• api.Navigator.taintEnabled (tested; data is correct)
• api.Window.beforeunload_event.event_returnvalue_activation
• api.Window.showModalDialog
• css.properties.overflow-x.auto (Fix overflow CSS prop support on Edge #23798)
• css.properties.overflow-y.auto (Fix overflow CSS prop support on Edge #23798)
• css.properties.overflow.auto (Fix overflow CSS prop support on Edge #23798)
• css.properties.text-combine-upright.digits
• css.selectors.placeholder-shown
• html.elements.iframe.sandbox.allow-same-origin
• html.elements.link.rel.alternate_stylesheet
• html.elements.link.rel.prerender
• html.elements.rb
• html.elements.rp (Mark <rp> and <rt> supported in Edge 12 #23791)
• html.elements.rt (Mark <rp> and <rt> supported in Edge 12 #23791)
• html.elements.source.height
• html.elements.source.width
• html.elements.wbr (Mark <wbr> supported in Edge 12 (most likely) #23804)
• svg.elements.circle.fill
• svg.elements.ellipse.fill
• svg.elements.path.fill
• svg.elements.pattern.href
• svg.elements.polygon.fill
• svg.elements.polyline.fill
• svg.elements.rect.fill
• svg.elements.text.fill
• svg.elements.textPath.fill
• svg.elements.tspan.fill

[foolip]

@captainbrosset @ddbeck FYI, anything in web-features that includes any of the above keys needs an extra look.

[captainbrosset]

@foolip I opened #23798 for the overflow CSS properties.