JS: prohibit declaration names that clash with JS builtin functions

See KT-18095, KT-17475, KT-18105, KT-5259

compiler/testData/diagnostics/testsWithJsStdLib/name/builtinClash.kt

@@ -0,0 +1,56 @@
+class C {
+    class <!JS_BUILTIN_NAME_CLASH!>prototype<!>
+
+    class <!JS_BUILTIN_NAME_CLASH!>length<!>
+
+    class <!JS_BUILTIN_NAME_CLASH!>`$metadata$`<!>
+
+    <!JS_BUILTIN_NAME_CLASH!>fun constructor()<!> {}
+}
+
+class D {
+    private class <!JS_BUILTIN_NAME_CLASH!>prototype<!>
+
+    private class <!JS_BUILTIN_NAME_CLASH!>length<!>
+
+    private class <!JS_BUILTIN_NAME_CLASH!>`$metadata$`<!>
+
+    private fun constructor() {}
+}
+
+class E {
+    @JsName("prototype")
+    class <!JS_BUILTIN_NAME_CLASH!>D<!>
+
+    <!JS_BUILTIN_NAME_CLASH!>@JsName("constructor")
+    fun f()<!> {}
+}
+
+class F {
+    @JsName("A")
+    class prototype
+
+    @JsName("B")
+    class length
+
+    @JsName("f")
+    fun constructor() {}
+}
+
+class prototype
+
+class length
+
+fun constructor() {
+}
+
+fun f() {
+    class prototype
+    class length
+
+    fun constructor() {}
+}
+
+external interface Object {
+    val constructor: Any?
+}