Use direct field access to trivial class properties

#KT-3845 Fixed

compiler/testData/codegen/bytecodeText/kt2202.kt

@@ -10,7 +10,7 @@ class A {
 
 class B {
     var foo = 1
-        private set
+        private set(value) { $foo = value }
 
     fun foo() {
        foo = 2

compiler/testData/codegen/bytecodeText/kt3845.kt

@@ -0,0 +1,41 @@
+class Example
+{
+    var a1 = 0
+
+    public var a2: Int = 0
+
+    private var a3 = 0
+
+
+    var b1 = 0
+        private set
+
+    var b2 = 0
+        internal set
+
+    var b3 = 0
+        set
+
+    public var b4: Int = 0
+        public set
+
+    private var b5 = 0
+        private set
+
+
+    {
+        a1 = 1
+        a2 = 1
+        a3 = 1
+
+        b1 = 1
+        b2 = 1
+        b3 = 1
+        b4 = 1
+        b5 = 1
+    }
+}
+
+// Every property should be accessed directly in this example because they all are final class properties with default accessors
+// 0 INVOKESPECIAL Example\.set
+// 0 INVOKEVIRTUAL Example\.set