JS: prohibit overriding external functions with optional parameters by non-external functions. See KT-13889

compiler/testData/diagnostics/testsWithJsStdLib/native/overrideOptionalParam.kt

@@ -0,0 +1,32 @@
+open external class A {
+    open fun f(x: Int = noImpl)
+}
+
+class B : A() {
+    <!OVERRIDING_EXTERNAL_FUN_WITH_OPTIONAL_PARAMS!>override fun f(x: Int)<!> {}
+}
+
+external class C : A() {
+    override fun f(x: Int) {}
+}
+
+
+external interface I {
+    fun f(x: Int = noImpl)
+}
+
+open external class D {
+    open fun f(x: Int)
+}
+
+class E : D() {
+    override fun f(x: Int) {}
+}
+
+class F : D(), I {
+    <!OVERRIDING_EXTERNAL_FUN_WITH_OPTIONAL_PARAMS!>override fun f(x: Int)<!> {}
+}
+
+external class G : D(), I {
+    override fun f(x: Int) {}
+}