[FIR] Consider @PlatformDependent annotation everywhere (including JS and Native)

^KT-57858 Fixed

Remove FirEmptyOverridesBackwardCompatibilityHelper since it's not used anymore

Remove overridesMemberWithPlatformDependent.kt test file since it becomes redundant

compiler/testData/codegen/box/annotations/platformDependent.kt

@@ -0,0 +1,26 @@
+// IGNORE_BACKEND_K1: JS, JS_IR, JS_IR_ES6, WASM, NATIVE
+// ISSUE: KT-57858
+
+// FILE: Sub.kt
+
+package kotlin.internal
+
+@Target(AnnotationTarget.FUNCTION)
+annotation class PlatformDependent
+
+// FILE: Main.kt
+
+@file:Suppress("INVISIBLE_MEMBER", "INVISIBLE_REFERENCE")
+
+import kotlin.internal.PlatformDependent
+
+interface I {
+    @PlatformDependent
+    fun f(): String = "FAIL"
+}
+
+class C : I {
+    fun f() = "OK"
+}
+
+fun box() = C().f()