KT-38450 Add functional interface converter to the NJ2K

- Enable custom compiler options for
`AbstractNewJavaToKotlinConverterSingleFileTest`
- ^KT-38450 Fixed

nj2k/testData/newJ2k/functionalInterfaces/AbstractGetter1.java

@@ -0,0 +1,6 @@
+// RUNTIME_WITH_FULL_JDK
+
+@FunctionalInterface
+public interface MyRunnable {
+    int getResult();
+}

nj2k/testData/newJ2k/functionalInterfaces/AbstractGetter1.kt

@@ -0,0 +1,4 @@
+// RUNTIME_WITH_FULL_JDK
+fun interface MyRunnable {
+    fun getResult(): Int
+}

nj2k/testData/newJ2k/functionalInterfaces/AbstractGetter2.java

@@ -0,0 +1,10 @@
+// RUNTIME_WITH_FULL_JDK
+
+@FunctionalInterface
+public interface MyRunnable {
+    int getResult();
+
+    default int getDoubleResult() {
+        return getResult() * 2;
+    }
+}

nj2k/testData/newJ2k/functionalInterfaces/AbstractGetter2.kt

@@ -0,0 +1,6 @@
+// RUNTIME_WITH_FULL_JDK
+fun interface MyRunnable {
+    fun getResult(): Int
+    val doubleResult: Int
+        get() = getResult() * 2
+}

nj2k/testData/newJ2k/functionalInterfaces/AbstractGetterNoFunctionalInterfaceAnnotation.java

@@ -0,0 +1,5 @@
+// RUNTIME_WITH_FULL_JDK
+
+public interface MyRunnable {
+    int getResult();
+}

nj2k/testData/newJ2k/functionalInterfaces/AbstractGetterNoFunctionalInterfaceAnnotation.kt

@@ -0,0 +1,4 @@
+// RUNTIME_WITH_FULL_JDK
+interface MyRunnable {
+    val result: Int
+}

nj2k/testData/newJ2k/functionalInterfaces/InterfacesHierarchy.java

@@ -0,0 +1,18 @@
+// RUNTIME_WITH_FULL_JDK
+
+// we intentionally do not convert interface to Kotlin fun interface
+// if it inherits from some other interface, because it is hard to deal
+// with default methods which were already converted to properties
+// (and in kotlin fun interface cannot have abstract property)
+
+public interface MyRunnableBase {
+    default int getValue() {
+        return 0;
+    }
+}
+
+@FunctionalInterface
+public interface MyRunnable extends MyRunnableBase {
+    @Override
+    int getValue();
+}

nj2k/testData/newJ2k/functionalInterfaces/InterfacesHierarchy.kt

@@ -0,0 +1,14 @@
+// RUNTIME_WITH_FULL_JDK
+// we intentionally do not convert interface to Kotlin fun interface
+// if it inherits from some other interface, because it is hard to deal
+// with default methods which were already converted to properties
+// (and in kotlin fun interface cannot have abstract property)
+interface MyRunnableBase {
+    val value: Int
+        get() = 0
+}
+
+@FunctionalInterface
+interface MyRunnable : MyRunnableBase {
+    abstract override val value: Int
+}

nj2k/testData/newJ2k/functionalInterfaces/MyRunnable.java

@@ -0,0 +1,6 @@
+// RUNTIME_WITH_FULL_JDK
+
+@FunctionalInterface
+public interface MyRunnable {
+    void run();
+}

nj2k/testData/newJ2k/functionalInterfaces/MyRunnable.kt

@@ -0,0 +1,4 @@
+// RUNTIME_WITH_FULL_JDK
+fun interface MyRunnable {
+    fun run()
+}

nj2k/testData/newJ2k/functionalInterfaces/NoFunctionalInterfaceAnnotation.java

@@ -0,0 +1,3 @@
+public interface MyRunnable {
+    void run();
+}

nj2k/testData/newJ2k/functionalInterfaces/NoFunctionalInterfaceAnnotation.kt

@@ -0,0 +1,3 @@
+interface MyRunnable {
+    fun run()
+}

nj2k/testData/newJ2k/functionalInterfaces/NoFunctionalInterfaceConversionEnabled.java

@@ -0,0 +1,7 @@
+// RUNTIME_WITH_FULL_JDK
+// COMPILER_ARGUMENTS: -XXLanguage:-FunctionalInterfaceConversion
+
+@FunctionalInterface
+public interface MyRunnable {
+    void run();
+}

nj2k/testData/newJ2k/functionalInterfaces/NoFunctionalInterfaceConversionEnabled.kt

@@ -0,0 +1,6 @@
+// RUNTIME_WITH_FULL_JDK
+// COMPILER_ARGUMENTS: -XXLanguage:-FunctionalInterfaceConversion
+@FunctionalInterface
+interface MyRunnable {
+    fun run()
+}

nj2k/testData/newJ2k/functionalInterfaces/SamMethodWithGenerics.java

@@ -0,0 +1,6 @@
+// RUNTIME_WITH_FULL_JDK
+
+@FunctionalInterface
+public interface MyRunnable {
+    <T> void process(T t);
+}

nj2k/testData/newJ2k/functionalInterfaces/SamMethodWithGenerics.kt

@@ -0,0 +1,5 @@
+// RUNTIME_WITH_FULL_JDK
+@FunctionalInterface
+interface MyRunnable {
+    fun <T> process(t: T)
+}