[TEST] Migrate AbstractDiagnosticsWithExplicitApi to new test runners

compiler/testData/diagnostics/tests/testsWithExplicitApi/toplevel.kt

@@ -0,0 +1,12 @@
+// SKIP_TXT
+
+/**
+ * foo KDoc
+ */
+<!NO_EXPLICIT_VISIBILITY_IN_API_MODE!>fun foo<!>() {}
+
+public fun foo2() {}
+
+<!NO_EXPLICIT_VISIBILITY_IN_API_MODE!>fun <!NO_EXPLICIT_RETURN_TYPE_IN_API_MODE!>bar<!><!>() = 10
+public fun <!NO_EXPLICIT_RETURN_TYPE_IN_API_MODE!>bar2<!>() = 10
+public fun bar3(): Int = 10