performance fixes

[normen662]

• change a ton of calls to semanticEquals(o, AliasMap.identitiesFor(...)) to semanticEquals(o, AliasMap.emptyMap())
• improve Ordering.normalizeOrderingSet() to not require the transitive closure anymore.

[foundationdb-ci]

Result of fdb-record-layer-pr on Linux CentOS 7

• Commit ID: 042eb0558d52187fe92910e523d27a976cf3d164
• Duration 0:15:09
• Result: :x: FAILED
• Error: Error while executing command: ./gradlew --no-daemon --console=plain -b ./build.gradle build destructiveTest -PcoreNotStrict -PreleaseBuild=false -PpublishBuild=false -PspotbugsEnableHtmlReport. Reason: exit status 1
• Build Log terminal output (available for 30 days)
• Build Workspace zip file of the working directory (available for 30 days)

[foundationdb-ci]

Result of fdb-record-layer-pr on Linux CentOS 7

• Commit ID: b3c28e2049debcd25f840d4b14d203901cadb941
• Duration 0:46:15
• Result: :white_check_mark: SUCCEEDED
• Error: N/A
• Build Log terminal output (available for 30 days)
• Build Workspace zip file of the working directory (available for 30 days)