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

js/js.translator/testData/box/callableReference/property/simpleMutableMember.kt

@@ -0,0 +1,19 @@
+// This test was adapted from compiler/testData/codegen/box/callableReference/property/.
+package foo
+
+data class Box(var value: String)
+
+fun box(): String {
+    val o = Box("lorem")
+    val prop = Box::value
+
+    if (prop.get(o) != "lorem") return "Fail 1: ${prop.get(o)}"
+    prop.set(o, "ipsum")
+    if (prop.get(o) != "ipsum") return "Fail 2: ${prop.get(o)}"
+    if (o.value != "ipsum") return "Fail 3: ${o.value}"
+    o.value = "dolor"
+    if (prop.get(o) != "dolor") return "Fail 4: ${prop.get(o)}"
+    if ("$o" != "Box(value=dolor)") return "Fail 5: $o"
+
+    return "OK"
+}