JetDiagnosticsTest migrated to TestGenerator

- test data files renamed from *.jet to *.kt

compiler/testData/diagnostics/tests/scopes/kt1822.kt

@@ -0,0 +1,30 @@
+//KT-1822 Error 'cannot infer visibility' required
+package kt1822
+
+open class C {
+    internal open fun foo() {}
+}
+
+trait T {
+    protected fun foo() {}
+}
+
+class G : C(), T {
+    <!CANNOT_INFER_VISIBILITY!>override fun foo()<!> {} //should be an error "cannot infer visibility"; for now 'public' is inferred in such cases
+}
+
+open class A {
+    internal open fun foo() {}
+}
+
+trait B {
+    protected fun foo() {}
+}
+
+trait D {
+    public fun foo() {}
+}
+
+class E : A(), B, D {
+    override fun foo() {}
+}