K2 Scripting: deprecate top level script inner classes

no LT support yet

compiler/testData/diagnostics/tests/script/NestedInnerClass.fir.kts

@@ -10,7 +10,7 @@ class Nested {
 }
 
 
-<!WRONG_MODIFIER_CONTAINING_DECLARATION!>inner<!> class Inner {
+<!INNER_ON_TOP_LEVEL_SCRIPT_CLASS_WARNING!>inner<!> class Inner {
     fun innerFun() = function()
     val innerProp = property
     fun innerThisFun() = this<!UNRESOLVED_LABEL!>@NestedInnerClass<!>.function()

compiler/testData/diagnostics/tests/script/innerClassError.fir.kts

@@ -0,0 +1,4 @@
+// TARGET_BACKEND: JVM_IR
+// !LANGUAGE: +ProhibitScriptTopLevelInnerClasses
+
+<!INNER_ON_TOP_LEVEL_SCRIPT_CLASS_ERROR!>inner<!> class A

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

@@ -0,0 +1,3 @@
+// TARGET_BACKEND: JVM_IR
+
+inner class A

compiler/testData/diagnostics/tests/script/innerClassWarning.fir.kts

@@ -0,0 +1,4 @@
+// TARGET_BACKEND: JVM_IR
+// !LANGUAGE: -ProhibitScriptTopLevelInnerClasses
+
+<!INNER_ON_TOP_LEVEL_SCRIPT_CLASS_WARNING!>inner<!> class A

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

@@ -0,0 +1,3 @@
+// TARGET_BACKEND: JVM_IR
+
+inner class A