Convert to expression body is forbidden on single non-exhaustive when statement with Unit result #KT-12502 Fixed

idea/testData/intentions/convertToExpressionBody/whenUnitWithElse.kt.after

@@ -0,0 +1,7 @@
+enum class AccessMode { READ, WRITE, RW }
+fun whenExpr(access: AccessMode) = when (access) {
+    AccessMode.READ -> println("read")
+    AccessMode.WRITE -> println("write")
+    else -> println("else")
+}
+fun println(s: String) {}