KT-23397 Optimize out field for property delegate when it's safe (JVM)

compiler/testData/codegen/box/delegatedProperty/delegateToThis/delegateToThisByExtension.kt

@@ -0,0 +1,13 @@
+// WITH_STDLIB
+// CHECK_BYTECODE_LISTING
+
+class C {
+    val s: String by this
+}
+
+val c = C()
+
+operator fun C.getValue(thisRef: Any?, property: Any?) =
+    if (this == c && thisRef == c) "OK" else "Failed"
+
+fun box() = c.s