[Test] Properly merge box against java testdata into codegen/box

Previous commit about it was 3199ce03 and it was completely wrong

compiler/testData/codegen/box/throws/delegationAndThrows_AgainstCompiled.kt

@@ -0,0 +1,25 @@
+// IGNORE_BACKEND_FIR: JVM_IR
+// DONT_TARGET_EXACT_BACKEND: JS JS_IR JS_IR_ES6 WASM NATIVE
+// TARGET_BACKEND: JVM
+// WITH_RUNTIME
+// MODULE: lib
+// FILE: A.java
+
+import java.io.IOException;
+
+public interface A {
+    void foo() throws IOException;
+}
+
+// MODULE: main(lib)
+// FILE: B.kt
+
+class B(a: A) : A by a
+
+fun box(): String {
+    val method = B::class.java.declaredMethods.single { it.name == B::foo.name }
+    if (method.exceptionTypes.size != 0)
+        return "Fail: ${method.exceptionTypes.toList()}"
+
+    return "OK"
+}