Debugger: Add a stepping test for inline classes (KT-26798)

idea/testData/debugger/tinyApp/src/stepping/stepInto/inlineClass.kt

@@ -0,0 +1,20 @@
+package inlineClass
+
+interface A {
+    fun foo()
+}
+
+@Suppress("EXPERIMENTAL_FEATURE_WARNING")
+inline class B(val a: String) : A {
+    override fun foo() {
+        println("foo")
+    }
+}
+
+fun main(args: Array<String>) {
+    val b = B("")
+    //Breakpoint!
+    b.foo()
+}
+
+// STEP_INTO: 1

idea/testData/debugger/tinyApp/src/stepping/stepInto/inlineClass.out

@@ -0,0 +1,9 @@
+LineBreakpoint created at inlineClass.kt:17
+Run Java
+Connected to the target VM
+inlineClass.kt:17
+inlineClass.kt:10
+Disconnected from the target VM
+
+Process finished with exit code 0
+foo