Initial implementation of platformStatic

compiler/testData/codegen/boxWithJava/platformStatic/classObject/simpleClassObject.kt

@@ -0,0 +1,22 @@
+class A {
+
+    class object {
+        val b: String = "OK"
+
+        platformStatic fun test1() = b
+
+        platformStatic fun test2() = b
+
+        platformStatic fun String.test3() = this + b
+    }
+}
+
+fun box(): String {
+    if (Test.test1() != "OK") return "fail 1"
+
+    if (Test.test2() != "OK") return "fail 2"
+
+    if (Test.test3() != "JAVAOK") return "fail 3"
+
+    return "OK"
+}