[FIR-TEST] Add new testdata generated after changes in previous commit

compiler/testData/diagnostics/tests/modifiers/internalInInterface.fir.kt

@@ -0,0 +1,7 @@
+interface My {
+    internal val x: Int
+    internal val xxx: Int
+        get() = 0
+    internal fun foo(): Int
+    internal fun bar() = 42
+}