Recognize if-like Tree.MultiSegmentApp as IfThenElse IR #1415

Job	Run time
🔍 Files Changed / Changed Files	6s
⚙️ Checks / Engine (GraalVM CE) (linux, amd64)	13m 33s
⚙️ Checks / Engine (GraalVM CE) (windows, amd64)	17m 27s
⚙️ Checks / JVM Tests (GraalVM CE) (linux, amd64)	16m 38s
⚙️ Checks / JVM Tests (GraalVM CE) (windows, amd64)	1h 36m 12s
⚙️ Checks / Standard Library Tests (GraalVM CE) (linux, amd64)	22m 0s
⚙️ Checks / Verify License Packages (linux, amd64)	1m 37s
⚙️ Checks / Standard Library Tests (GraalVM CE) (windows, amd64)	31m 10s
⚙️ Checks (Optional) / Engine (GraalVM CE) (macos, amd64)	48m 47s
⚙️ Checks (Optional) / JVM Tests (GraalVM CE) (macos, amd64)	1h 4m 32s
⚙️ Checks (Optional) / Standard Library Tests (GraalVM CE) (macos, amd64)	46m 50s
Engine Required Checks	1s
	5h 58m 53s

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