[FIR2IR] Provide remapped f/o symbols to declaration storage

After a generation of fake overrides some code may still to refer old
  symbols from declaration storage (like computation of overridden
  symbols for lazy functions), so we need to remap those symbols using
  information from IR f/o generator

compiler/testData/codegen/box/fakeOverride/intersectionOverrideBetweenValAndVar.kt

@@ -0,0 +1,24 @@
+// DUMP_IR
+// FIR_IDENTICAL
+
+abstract class A {
+    abstract val x: String
+}
+
+interface B {
+    var x: String
+}
+
+abstract class C : A(), B
+
+class D(override var x: String) : C()
+
+fun test(c: C) {
+    c.x = "OK"
+}
+
+fun box(): String {
+    val d = D("Fail")
+    test(d)
+    return d.x
+}