K2 Scripting tests: adding tests on script decls visibility

fixes (makes it stable) behavior of the script top-level declarations
visibility in K2 scripts

compiler/testData/diagnostics/tests/script/scriptDeclsShouldVisibleLocally.kts

@@ -0,0 +1,25 @@
+// FIR_IDENTICAL
+
+val a = 42
+
+class A
+
+enum class E {
+    V
+}
+
+object O {
+    val v = 42
+}
+
+fun foo() = 42
+
+val b =  a
+
+val ca = A()
+
+val ev = E.V
+
+val ov = O.v
+
+val rfoo = foo()