Debugger: Allow to touch experimental stuff from evaluator (KT-30216)

idea/testData/debugger/tinyApp/src/evaluate/singleBreakpoint/experimentalApi.kt

@@ -0,0 +1,15 @@
+package experimentalApi
+
+@Experimental(Experimental.Level.ERROR)
+annotation class UnstableApi
+
+@UnstableApi
+fun foo() = 5
+
+fun main() {
+    //Breakpoint!
+    val a = 5
+}
+
+// EXPRESSION: foo()
+// RESULT: 5: I

idea/testData/debugger/tinyApp/src/evaluate/singleBreakpoint/experimentalApi.out

@@ -0,0 +1,8 @@
+LineBreakpoint created at experimentalApi.kt:11
+Run Java
+Connected to the target VM
+experimentalApi.kt:11
+Compile bytecode for foo()
+Disconnected from the target VM
+
+Process finished with exit code 0