JS: prohibit stable (public) names with non-identifier chars. Rewrite unstable (private) names with non-identifier chars. See KT-4160

js/js.translator/testData/box/jsName/peculiarIdentifiers.kt

@@ -0,0 +1,34 @@
+private fun `+`(a: Int, b: Int) = a + b
+
+@JsName("minus")
+fun `-`(a: Int, b: Int) = a - b
+
+fun test1(): Int {
+    val ` x ` = 23
+    val `*` = 3
+    return `-`(` x `, `*`)
+}
+
+fun test2(`p 1`: Int, `.p 2`: Int) = `+`(`p 1`, `.p 2`)
+
+fun test3(): String {
+    val `#` = "K"
+    class ` `(private val `::`: String) {
+        internal fun `@`() = `::` + `#`
+    }
+    return ` `("O").`@`()
+}
+
+fun test4(): String {
+    val `()` = "OK"
+    fun `[]`() = `()`
+    return `[]`()
+}
+
+fun box(): String {
+    if (test1() != 20) return "fail1"
+    if (test2(10, 13) != 23) return "fail2"
+    if (test3() != "OK") return "fail3"
+    if (test4() != "OK") return "fail4"
+    return "OK"
+}

js/js.translator/testData/jsTester/jsTester.kt

@@ -8,8 +8,6 @@ public class JsTestsAsserter() : Asserter {
     public override fun fail(message: String?): Nothing = failWithMessage(message)
 }
 
-@JsName("JsTests.assert")
-public external fun assert(value: Boolean, message: String?): Unit = noImpl
+public inline fun assert(value: Boolean, message: String?): Unit = js("JsTests").assert(value, message)
 
-@JsName("JsTests.fail")
-private external fun failWithMessage(message: String?): Nothing = noImpl
+private inline fun failWithMessage(message: String?): Nothing = js("JsTests").fail(message)