Generate copy function for data classes

#KT-2779 Fixed

compiler/testData/codegen/dataClasses/copy/constructorWithDefaultParam.kt

@@ -0,0 +1,29 @@
+data class A(val a: Int = 1, val b: String = "$a") {}
+
+fun box() : String {
+    var result = ""
+    val a = A()
+    val b = a.copy()
+    if (b.a == 1 && b.b == "1") {
+        result += "1"
+    }
+
+    val c = a.copy(a = 2)
+    if (c.a == 2 && c.b == "1") {
+        result += "2"
+    }
+
+    val d = a.copy(b = "2")
+    if (d.a == 1 && d.b == "2") {
+        result += "3"
+    }
+
+    val e = a.copy(a = 2, b = "2")
+    if (e.a == 2 && e.b == "2") {
+        result += "4"
+    }
+    if (result == "1234") {
+        return "OK"
+    }
+    return "fail"
+}

compiler/testData/codegen/dataClasses/copy/paramWithoutProperty.kt

@@ -0,0 +1,17 @@
+data class A(a: Int, b: String) {}
+
+fun box() : String {
+    for (method in javaClass<A>().getDeclaredMethods()) {
+        if (method.getName() == "copy"){
+            val parameterTypes = method.getParameterTypes()
+            if (parameterTypes != null && parameterTypes.size == 2) {
+                val copy = A(1, "a").copy(a = 2, b = "b")
+                return "OK"
+            }
+            else {
+                return "Method copy has " + (if (parameterTypes == null) "0" else parameterTypes.size) + " parameters, expected 2"
+            }
+        }
+    }
+    return "fail"
+}

compiler/testData/codegen/dataClasses/copy/valInConstructorParams.kt

@@ -0,0 +1,29 @@
+data class A(val a: Int, val b: String) {}
+
+fun box() : String {
+    var result = ""
+    val a = A(1, "a")
+    val b = a.copy()
+    if (b.a == 1 && b.b == "a") {
+        result += "1"
+    }
+
+    val c = a.copy(a = 2)
+    if (c.a == 2 && c.b == "a") {
+        result += "2"
+    }
+
+    val d = a.copy(b = "b")
+    if (d.a == 1 && d.b == "b") {
+        result += "3"
+    }
+
+    val e = a.copy(a = 2, b = "b")
+    if (e.a == 2 && e.b == "b") {
+        result += "4"
+    }
+    if (result == "1234") {
+        return "OK"
+    }
+    return "fail"
+}

compiler/testData/codegen/dataClasses/copy/varInConstructorParams.kt

@@ -0,0 +1,29 @@
+data class A(var a: Int, var b: String) {}
+
+fun box() : String {
+    var result = ""
+    val a = A(1, "a")
+    val b = a.copy()
+    if (b.a == 1 && b.b == "a") {
+        result += "1"
+    }
+
+    val c = a.copy(a = 2)
+    if (c.a == 2 && c.b == "a") {
+        result += "2"
+    }
+
+    val d = a.copy(b = "b")
+    if (d.a == 1 && d.b == "b") {
+        result += "3"
+    }
+
+    val e = a.copy(a = 2, b = "b")
+    if (e.a == 2 && e.b == "b") {
+        result += "4"
+    }
+    if (result == "1234") {
+        return "OK"
+    }
+    return "fail"
+}

compiler/testData/codegen/dataClasses/copy/withGenericParameter.kt

@@ -0,0 +1,14 @@
+data class A(val a: Foo<String>) {}
+
+class Foo<T>(val a: T) { }
+
+fun box() : String {
+    val f1 = Foo("a")
+    val f2 = Foo("b")
+    val a = A(f1)
+    val b = a.copy(f2)
+    if (b.a.a == "b") {
+        return "OK"
+    }
+    return "fail"
+}