FIR: introduce diagnostic NESTED_CLASS_NOT_ALLOWED

compiler/testData/diagnostics/tests/enum/dontCreatePackageTypeForEnumEntry_after.fir.kt

@@ -1,16 +0,0 @@
-// !LANGUAGE: +NestedClassesInEnumEntryShouldBeInner
-
-enum class E {
-    FIRST,
-    SECOND {
-        class A
-    };
-}
-
-val foo: Any.() -> Unit = {}
-
-fun f1() = E.FIRST.foo()
-fun f2() = E.FIRST.(foo)()
-fun f3() = E.SECOND.foo()
-fun f4() = E.SECOND.(foo)()
-fun f5() = E.SECOND.<!UNRESOLVED_REFERENCE!>A<!>()

compiler/testData/diagnostics/tests/enum/dontCreatePackageTypeForEnumEntry_after.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // !LANGUAGE: +NestedClassesInEnumEntryShouldBeInner
 
 enum class E {

compiler/testData/diagnostics/tests/enum/dontCreatePackageTypeForEnumEntry_before.fir.kt

@@ -3,7 +3,7 @@
 enum class E {
     FIRST,
     SECOND {
-        class A
+        <!NESTED_CLASS_NOT_ALLOWED!>class A<!>
     };
 }
 

compiler/testData/diagnostics/tests/enum/inner/insideInnerClassNotAllowed.fir.kt

@@ -1,7 +0,0 @@
-class A {
-    inner class B {
-        enum class E {
-            ENTRY
-        }
-    }
-}

compiler/testData/diagnostics/tests/enum/inner/insideInnerClassNotAllowed.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 class A {
     inner class B {
         <!NESTED_CLASS_NOT_ALLOWED!>enum class E<!> {

compiler/testData/diagnostics/tests/enum/inner/twoEnumsInClassObjectAndInnerClass.fir.kt

@@ -1,9 +0,0 @@
-class A {
-    companion object {
-        enum class E { ENTRY }  // OK
-    }
-    
-    inner class B {
-        enum class E { ENTRY }
-    }
-}

compiler/testData/diagnostics/tests/enum/inner/twoEnumsInClassObjectAndInnerClass.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 class A {
     companion object {
         enum class E { ENTRY }  // OK