Java to Kotlin converter: converting usages of Kotlin object members

#KT-5172 Fixed

j2k/src/org/jetbrains/jet/j2k/visitors/ExpressionVisitor.kt

@@ -294,7 +294,7 @@ open class ExpressionVisitor(protected val converter: Converter,
             identifier = Identifier("size", isNullable)
         }
         else if (qualifier != null) {
-            if (referencedName == "object$") {
+            if (referencedName == "object$" || referencedName == "instance$") {
                 val target = expression.getReference()?.resolve()
                 if (target is LightField) { //TODO: should be KotlinLightField with check of origin here, see KT-5188
                     result = converter.convertExpression(qualifier)

j2k/tests/test/org/jetbrains/jet/j2k/test/JavaToKotlinConverterTestGenerated.java

@@ -1596,6 +1596,11 @@ public class JavaToKotlinConverterTestGenerated extends AbstractJavaToKotlinConv
             doTest("j2k/tests/testData/ast/kotlinApiAccess/InheritedProperty.java");
         }
         
+        @TestMetadata("ObjectMembers.java")
+        public void testObjectMembers() throws Exception {
+            doTest("j2k/tests/testData/ast/kotlinApiAccess/ObjectMembers.java");
+        }
+        
         @TestMetadata("Property.java")
         public void testProperty() throws Exception {
             doTest("j2k/tests/testData/ast/kotlinApiAccess/Property.java");

j2k/tests/testData/KotlinApi.kt

@@ -7,8 +7,8 @@ public open class KotlinClass {
         public fun statucFun(p: Int): Int = p
         public var staticVar: Int = 1
         public var staticProperty: Int
-          get() = 1
-          set(value) {}
+            get() = 1
+            set(value) {}
     }
 }
 
@@ -19,9 +19,17 @@ public fun Int.extensionFunction(): String = toString()
 
 public var globalValue1: Int = 1
 public var globalValue2: Int
-  get() = 0
-  set(value) {}
+    get() = 0
+    set(value) {}
 
 public var String.extensionProperty: Int
   get() = 1
-  set(value) {}
+  set(value) {}
+
+public object KotlinObject {
+    public fun foo(): Int = 1
+    public var property1: Int = 1
+    public var property2: Int
+        get() = 1
+        set(value) {}
+}

j2k/tests/testData/ast/kotlinApiAccess/ObjectMembers.java

@@ -0,0 +1,12 @@
+//file
+import kotlinApi.KotlinObject;
+
+class C {
+    int foo() {
+        KotlinObject.instance$.setProperty1(1);
+        KotlinObject.instance$.setProperty2(2);
+        return KotlinObject.instance$.foo() +
+               KotlinObject.instance$.getProperty1() +
+               KotlinObject.instance$.getProperty2();
+    }
+}

j2k/tests/testData/ast/kotlinApiAccess/ObjectMembers.kt

@@ -0,0 +1,9 @@
+import kotlinApi.KotlinObject
+
+class C() {
+    fun foo(): Int {
+        KotlinObject.property1 = 1
+        KotlinObject.property2 = 2
+        return KotlinObject.foo() + KotlinObject.property1 + KotlinObject.property2
+    }
+}