JS: create new common directory for all generated tests, migrate several tests there

js/js.translator/testData/box/inline/multiDeclaration.kt

@@ -0,0 +1,17 @@
+package foo
+
+// CHECK_NOT_CALLED: component1
+// CHECK_NOT_CALLED: component2
+
+class A(val a: Int, val b: Int)
+
+inline operator fun A.component1(): Int = a
+inline operator fun A.component2(): Int = b
+
+fun box(): String {
+    val (a, b) = A(1, 2)
+    assertEquals(1, a)
+    assertEquals(2, b)
+
+    return "OK"
+}