JVM_IR: optimize delegation by property references

E.g. a statement like

    var x by ::y

is semantically equivalent to

    var x
      get() = y
      set(value) { y = value }

and thus does not need a full property reference object, or even a field
if the receiver is not bound.

 #KT-39054 Fixed
 #KT-47102 Fixed

compiler/testData/codegen/box/delegatedProperty/delegateToAnother.kt

@@ -1,4 +1,3 @@
-// WITH_REFLECT
 // WITH_RUNTIME
 class C(val x: String)
 

compiler/testData/codegen/box/delegatedProperty/delegateToAnotherMutable.kt

@@ -0,0 +1,13 @@
+// WITH_RUNTIME
+// IGNORE_BACKEND: JS
+class C(var x: String)
+
+var x = "fail"
+var y by ::x
+var z by C("fail")::x
+
+fun box(): String {
+    y = "O"
+    z = "K"
+    return y + z
+}

compiler/testData/codegen/box/delegatedProperty/delegateToGenericJavaProperty.kt

@@ -0,0 +1,26 @@
+// TARGET_BACKEND: JVM
+// v-- fir2ir produces an IrFunctionReference of type KProperty0 instead of an IrPropertyReference
+// IGNORE_BACKEND_FIR: JVM_IR
+// WITH_REFLECT
+// WITH_RUNTIME
+// FILE: J.java
+public interface J<T> {
+    public T getValue();
+}
+
+// FILE: box.kt
+class Impl(val x: String) : J<String> {
+    override fun getValue() = x
+}
+
+val j1: J<String> = Impl("O")
+// Note that taking a reference to `J<T>::value` is not permitted by the frontend
+// in any context except as a direct argument to `by`; e.g. `val x by run { j1::value }`
+// would produce an error.
+val x by j1::value
+
+fun box(): String {
+    val j2: J<String> = Impl("K")
+    val y by j2::value
+    return x + y
+}