Deprecate PropertyMetadata, use KProperty<*> for delegated properties instead

compiler/testData/diagnostics/tests/delegatedProperty/backingField.kt

@@ -1,5 +1,7 @@
 // !DIAGNOSTICS: -UNUSED_PARAMETER
 
+import kotlin.reflect.KProperty
+
 class B {
     val a: Int by Delegate()
 
@@ -7,8 +9,7 @@ class B {
 }
 
 class Delegate {
-  operator fun getValue(t: Any?, p: PropertyMetadata): Int {
+  operator fun getValue(t: Any?, p: KProperty<*>): Int {
     return 1
   }
 }
-