Fix KClass.java intrinsic for stack values of type Unit

#KT-17692 Fixed

compiler/backend/src/org/jetbrains/kotlin/codegen/intrinsics/JavaClassProperty.kt

@@ -24,6 +24,7 @@ import org.jetbrains.kotlin.codegen.ExpressionCodegen
 import org.jetbrains.kotlin.codegen.StackValue
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor
 import org.jetbrains.kotlin.resolve.calls.model.ResolvedCall
+import org.jetbrains.kotlin.resolve.jvm.AsmTypes.UNIT_TYPE
 import org.jetbrains.kotlin.resolve.jvm.AsmTypes.getType
 import org.jetbrains.org.objectweb.asm.Type
 import org.jetbrains.org.objectweb.asm.commons.InstructionAdapter
@@ -42,7 +43,12 @@ object JavaClassProperty : IntrinsicPropertyGetter() {
 
     fun generateImpl(v: InstructionAdapter, receiver: StackValue): Type {
         val type = receiver.type
-        if (isPrimitive(type)) {
+        if (type == Type.VOID_TYPE) {
+            receiver.put(Type.VOID_TYPE, v)
+            StackValue.unit().put(UNIT_TYPE, v)
+            v.invokevirtual("java/lang/Object", "getClass", "()Ljava/lang/Class;", false)
+        }
+        else if (isPrimitive(type)) {
             if (!StackValue.couldSkipReceiverOnStaticCall(receiver)) {
                 receiver.put(type, v)
                 AsmUtil.pop(v, type)
@@ -61,12 +67,7 @@ object JavaClassProperty : IntrinsicPropertyGetter() {
         val classType = codegen.state.typeMapper.mapType(resolvedCall.call.dispatchReceiver!!.type)
         return object : IntrinsicCallable(getType(Class::class.java), listOf(), classType, null) {
             override fun invokeIntrinsic(v: InstructionAdapter) {
-                if (isPrimitive(classType)) {
+                generateImpl(v, StackValue.none())
-                    v.getstatic(boxType(classType).internalName, "TYPE", "Ljava/lang/Class;")
-                }
-                else {
-                    v.invokevirtual("java/lang/Object", "getClass", "()Ljava/lang/Class;", false)
-                }
             }
 
             override fun isStaticCall() = isPrimitive(classType)

compiler/testData/codegen/box/callableReference/bound/localUnitFunction.kt

@@ -0,0 +1,9 @@
+// TARGET_BACKEND: JVM
+// WITH_RUNTIME
+
+fun box(): String {
+    fun foo(): Unit {}
+    assert(Unit.javaClass.equals(foo().javaClass))
+    assert(Unit.javaClass.equals(foo()::class.java))
+    return "OK"
+}

compiler/tests-ir-jvm/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java

@@ -1621,6 +1621,12 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
                 doTest(fileName);
             }
 
+            @TestMetadata("localUnitFunction.kt")
+            public void testLocalUnitFunction() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/callableReference/bound/localUnitFunction.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("multiCase.kt")
             public void testMultiCase() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/callableReference/bound/multiCase.kt");

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

@@ -1621,6 +1621,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("localUnitFunction.kt")
+            public void testLocalUnitFunction() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/callableReference/bound/localUnitFunction.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("multiCase.kt")
             public void testMultiCase() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/callableReference/bound/multiCase.kt");

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

@@ -1621,6 +1621,12 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
                 doTest(fileName);
             }
 
+            @TestMetadata("localUnitFunction.kt")
+            public void testLocalUnitFunction() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/callableReference/bound/localUnitFunction.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("multiCase.kt")
             public void testMultiCase() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/callableReference/bound/multiCase.kt");