FE 1.0: spread OptIn markers to children except fake override case

#KT-49001 Fixed

compiler/testData/diagnostics/testsWithStdLib/experimental/classMembers.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // !OPT_IN: kotlin.RequiresOptIn
 // FILE: api.kt
 
@@ -81,9 +82,9 @@ import api.*
 
 fun use() {
     val c: <!OPT_IN_USAGE!>C<!> = <!OPT_IN_USAGE!>C<!>()
-    <!OPT_IN_USAGE!>c<!>.function()
-    <!OPT_IN_USAGE!>c<!>.property
-    <!OPT_IN_USAGE!>C<!>.Nested()
-    <!OPT_IN_USAGE!>c<!>.Inner()
+    <!OPT_IN_USAGE!>c<!>.<!OPT_IN_USAGE!>function<!>()
+    <!OPT_IN_USAGE!>c<!>.<!OPT_IN_USAGE!>property<!>
+    <!OPT_IN_USAGE!>C<!>.<!OPT_IN_USAGE!>Nested<!>()
+    <!OPT_IN_USAGE!>c<!>.<!OPT_IN_USAGE!>Inner<!>()
     <!OPT_IN_USAGE!>c<!>.<!OPT_IN_USAGE!>extension<!>()
 }