[KT-10614] Fix issue: copy array on vararg call with spread operator

js/js.translator/src/org/jetbrains/kotlin/js/translate/reference/CallArgumentTranslator.kt

@@ -237,6 +237,9 @@ class CallArgumentTranslator private constructor(
                 val concatExpression = concatArgumentsIfNeeded(concatArguments)
                 result.add(concatExpression)
             }
+            else if (result.size == 1) {
+                result[0] = JsAstUtils.invokeMethod(result[0], "slice")
+            }
 
             return resultKind
         }

js/js.translator/testData/expression/function/cases/vararg.kt

@@ -103,5 +103,8 @@ fun box(): String {
     assertEquals(3, idArrayVarArg(arrayOf(1, 2), *arrayOf(arrayOf(3, 4), arrayOf(5, 6))).size)
     assertEquals(6, idArrayVarArg(arrayOf(1, 2), *arrayOf(arrayOf(3, 4), arrayOf(5, 6)), arrayOf(7), *arrayOf(arrayOf(8, 9), arrayOf(10, 11))).size)
 
+    val c = arrayOf(*a)
+    assertFalse(a === c, "Spread operator should copy its argument")
+
     return "OK"
 }