PlatformInfo tries to memoize calls to xcodebuild to determine SDKs and Xcode version, but there isn't a singleton PlatformInfo, so it doesn't work. Fixing this reduces the time to run a single test from ~7 seconds to ~3.
<rdar://problem/69377368>
https://github.com/WebKit/WebKit/pull/1941
kimmo++, thank you for fixing :)
Committed 252047@main (bac2308618bb): <https://commits.webkit.org/252047@main> Reviewed commits have been landed. Closing PR #1941 and removing active labels.