Write generic signature for autogenerated toArray

#KT-14195 Fixed

compiler/backend/src/org/jetbrains/kotlin/codegen/ImplementationBodyCodegen.java

@@ -457,7 +457,8 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
         }
 
         if (!hasGenericToArray) {
-            MethodVisitor mv = v.newMethod(NO_ORIGIN, ACC_PUBLIC, "toArray", "([Ljava/lang/Object;)[Ljava/lang/Object;", null, null);
+            MethodVisitor mv = v.newMethod(
+                    NO_ORIGIN, ACC_PUBLIC, "toArray", "([Ljava/lang/Object;)[Ljava/lang/Object;", "<T:Ljava/lang/Object;>([TT;)[TT;", null);
 
             InstructionAdapter iv = new InstructionAdapter(mv);
             mv.visitCode();

compiler/testData/codegen/box/collections/toArrayInJavaClass.kt

@@ -0,0 +1,32 @@
+// WITH_RUNTIME
+// FILE: B.java
+public class B<E> extends A<E> {
+    @Override
+    public <T> T[] toArray(T[] a) {
+        return a;
+    }
+}
+
+// FILE: main.kt
+open class A<T> : Collection<T> {
+    override val size: Int
+        get() = TODO("not implemented") //To change initializer of created properties use File | Settings | File Templates.
+
+    override fun contains(element: T): Boolean {
+        TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
+    }
+
+    override fun containsAll(elements: Collection<T>): Boolean {
+        TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
+    }
+
+    override fun isEmpty(): Boolean {
+        TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
+    }
+
+    override fun iterator(): Iterator<T> {
+        TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
+    }
+}
+
+fun box() = B<String>().toArray(arrayOf("OK"))[0]

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -3615,6 +3615,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/collections/strList.kt");
             doTest(fileName);
         }
+
+        @TestMetadata("toArrayInJavaClass.kt")
+        public void testToArrayInJavaClass() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/collections/toArrayInJavaClass.kt");
+            doTest(fileName);
+        }
     }
 
     @TestMetadata("compiler/testData/codegen/box/compatibility")