Fix issues with enum entry self-reference

Given a singleton class 'S' with possibly uninitialized static instance
(enum entry, interface companion object).
Such singleton can be referenced by name, or as an explicit or implicit
'this'.
For a given singleton class 'S' we
either use 'this@S' from context (local or captured),
or 'S' as a static instance.

Local or captured 'this@S' should be used if:
  - we are in the constructor for 'S',
    and corresponding instance is initialized
        by super or delegating constructor call;
  - we are in any other member of 'S' or any of its inner classes.

Otherwise, a static instance should be used.

compiler/testData/codegen/box/enum/enumEntryReferenceFromInnerClassConstructor1.kt

@@ -0,0 +1,24 @@
+interface IFoo {
+    fun foo(): String
+}
+
+interface IBar {
+    fun bar(): String
+}
+
+abstract class Base(val x: IFoo)
+
+enum class Test : IFoo, IBar {
+    FOO {
+        // FOO referenced from inner class constructor with uninitialized 'this'
+        inner class Inner : Base(FOO)
+
+        val z = Inner()
+
+        override fun foo() = "OK"
+
+        override fun bar() = z.x.foo()
+    }
+}
+
+fun box() = Test.FOO.bar()