[Wasm] Fix SuspendFunctionKind.DELEGATING bug (KT-60700)

When detecting function delegation at the last statement position we
need to make sure that delegating call has unit return type, otherwise
we would try to return non-Unit value from a parent function returning
 Unit

^KT-60700 Fixed

compiler/testData/codegen/box/callableReference/adaptedReferences/suspendUnitConversion.kt

@@ -12,8 +12,6 @@ suspend fun bar(): Int = suspendCoroutineUninterceptedOrReturn<Int> {
 }
 
 fun box(): String {
-    return "OK" // KT-60700 Test is hardmuted due to WASM failures on Win&Mac, but not on Linux. So, `// IGNORE_BACKEND: WASM` does not help
-
     var result = ""
     suspend {
         foo(::bar)