Simplify property hierarchy in reflection

Leave only 3*2 = 6 classes: KProperty0, KProperty1, KProperty2 and their
mutable analogs, depending on the number of receivers a property takes

compiler/testData/codegen/boxWithStdlib/platformStatic/callableRef.kt

@@ -4,7 +4,7 @@ object A {
 
     val b: String = "OK"
 
-    platformStatic val c: String = "OK"
+    platformStatic var c: String = "Fail"
 
     platformStatic fun test1() : String {
         return b
@@ -36,6 +36,8 @@ fun box(): String {
 
     if ((A::test4)(A) != "1OK") return "fail 4"
 
+    (A::c).set(A, "OK")
+
     if (((A::c).get(A)) != "OK") return "fail 5"
 
     return "OK"