EA-219152 (partially): Support KClass 'unboxing' in debugger

KClass can be 'unboxed' to a plain Java class. Debugger should be aware of this.
Unfortunately, this commit is not enough to fully support this scenario, as it's impossible to invoke KClass methods/extension on java.lang.Class instance. There should be an additional diagnostic that will forbid such calls.

idea/jvm-debugger/jvm-debugger-evaluation/src/org/jetbrains/kotlin/idea/debugger/evaluate/variables/EvaluatorValueConverter.kt

@@ -50,6 +50,11 @@ class EvaluatorValueConverter(val context: ExecutionContext) {
             return true
         }
 
+        if (requestedType == AsmTypes.K_CLASS_TYPE && actualType == AsmTypes.JAVA_CLASS_TYPE) {
+            // KClass can be represented as a Java class for simpler cases. See BoxingInterpreter.isJavaLangClassBoxing().
+            return true
+        }
+
         val unwrappedActualType = unwrap(actualType)
         val unwrappedRequestedType = unwrap(requestedType)
         return unwrappedActualType == unwrappedRequestedType

idea/jvm-debugger/jvm-debugger-test/test/org/jetbrains/kotlin/idea/debugger/test/KotlinEvaluateExpressionTestGenerated.java

@@ -260,6 +260,11 @@ public class KotlinEvaluateExpressionTestGenerated extends AbstractKotlinEvaluat
             runTest("idea/jvm-debugger/jvm-debugger-test/testData/evaluation/singleBreakpoint/javaStaticMethods.kt");
         }
 
+        @TestMetadata("kClass.kt")
+        public void testKClass() throws Exception {
+            runTest("idea/jvm-debugger/jvm-debugger-test/testData/evaluation/singleBreakpoint/kClass.kt");
+        }
+
         @TestMetadata("kt12206BasePropertyWithoutBackingField.kt")
         public void testKt12206BasePropertyWithoutBackingField() throws Exception {
             runTest("idea/jvm-debugger/jvm-debugger-test/testData/evaluation/singleBreakpoint/kt12206BasePropertyWithoutBackingField.kt");

idea/jvm-debugger/jvm-debugger-test/testData/evaluation/singleBreakpoint/kClass.kt

@@ -0,0 +1,23 @@
+package test
+
+class Foo
+
+fun main() {
+    val cls = Foo::class
+    val cls2 = Foo::class
+    val cls3 = Foo::class.java
+
+    //Breakpoint!
+    foo(cls2)
+}
+
+private fun foo(a: Any?) {}
+
+// EXPRESSION: cls
+// RESULT: instance of java.lang.Class(reflected class=test.Foo, id=ID): Ljava/lang/Class;
+
+// EXPRESSION: cls2
+// RESULT: instance of kotlin.jvm.internal.ClassReference(id=ID): Lkotlin/jvm/internal/ClassReference;
+
+// EXPRESSION: cls3
+// RESULT: instance of java.lang.Class(reflected class=test.Foo, id=ID): Ljava/lang/Class;

idea/jvm-debugger/jvm-debugger-test/testData/evaluation/singleBreakpoint/kClass.out

@@ -0,0 +1,10 @@
+LineBreakpoint created at kClass.kt:11
+Run Java
+Connected to the target VM
+kClass.kt:11
+Compile bytecode for cls
+Compile bytecode for cls2
+Compile bytecode for cls3
+Disconnected from the target VM
+
+Process finished with exit code 0