Convert to expression body: take nested whens into account

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

@@ -0,0 +1,11 @@
+// IS_APPLICABLE: true
+enum class AccessMode { READ, WRITE, RW }
+fun <T> run(f: () -> T) = f()
+fun whenExpr(access: AccessMode) = run {
+    println("run")
+    when (access) {
+        AccessMode.READ -> println("read")
+        AccessMode.WRITE -> println("write")
+    }
+}
+fun println(s: String) {}