feat(Escaped Identifiers): add ability to use any symbol wrapped in back ticks.

js/js.translator/testData/box/escapedIdentifiers/classLikeMemberFunctionMangling.kt

@@ -0,0 +1,47 @@
+// IGNORE_BACKEND: JS
+// !LANGUAGE: +JsAllowInvalidCharsIdentifiersEscaping
+
+package foo
+
+interface IA {
+    fun `run•invalid@test`(): Int
+    fun `run@invalid@test`(): Int
+    fun run_invalid_test(): Int
+}
+
+@JsExport()
+class A : IA {
+    override fun `run•invalid@test`(): Int = 41
+    override fun `run@invalid@test`(): Int = 34
+    override fun run_invalid_test(): Int = 23
+}
+
+class B : IA {
+    override fun `run•invalid@test`(): Int = 42
+    override fun `run@invalid@test`(): Int = 35
+    override fun run_invalid_test(): Int = 24
+}
+
+fun box(): String {
+    val a: IA = A()
+    val b: IA = B()
+
+    assertEquals(23, a.run_invalid_test())
+    assertEquals(24, b.run_invalid_test())
+
+    assertEquals(34, a.`run@invalid@test`())
+    assertEquals(35, b.`run@invalid@test`())
+
+    assertEquals(41, a.`run•invalid@test`())
+    assertEquals(42, b.`run•invalid@test`())
+
+    assertEquals("function", js("typeof a['run•invalid@test']"))
+    assertEquals(41, js("a['run•invalid@test']()"))
+    assertEquals(js("undefined"), js("b['run•invalid@test']"))
+
+    assertEquals("function", js("typeof a['run@invalid@test']"))
+    assertEquals(34, js("a['run@invalid@test']()"))
+    assertEquals(js("undefined"), js("b['run@invalid@test']"))
+
+    return "OK"
+}