[FIR] Missing NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE

^KT-59433 Fixed

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDataClassConverters.kt

@@ -524,6 +524,13 @@ internal val KT_DIAGNOSTIC_CONVERTER = KtDiagnosticConverterBuilder.buildConvert
             token,
         )
     }
+    add(FirErrors.NESTED_CLASS_ACCESSED_VIA_INSTANCE_REFERENCE) { firDiagnostic ->
+        NestedClassAccessedViaInstanceReferenceImpl(
+            firSymbolBuilder.classifierBuilder.buildClassLikeSymbol(firDiagnostic.a),
+            firDiagnostic as KtPsiDiagnostic,
+            token,
+        )
+    }
     add(FirErrors.SUPER_IS_NOT_AN_EXPRESSION) { firDiagnostic ->
         SuperIsNotAnExpressionImpl(
             firDiagnostic as KtPsiDiagnostic,

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDiagnostics.kt

@@ -414,6 +414,11 @@ sealed interface KtFirDiagnostic<PSI : PsiElement> : KtDiagnosticWithPsi<PSI> {
         val suggestedFunction: String
     }
 
+    interface NestedClassAccessedViaInstanceReference : KtFirDiagnostic<PsiElement> {
+        override val diagnosticClass get() = NestedClassAccessedViaInstanceReference::class
+        val symbol: KtClassLikeSymbol
+    }
+
     interface SuperIsNotAnExpression : KtFirDiagnostic<PsiElement> {
         override val diagnosticClass get() = SuperIsNotAnExpression::class
     }

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/diagnostics/KtFirDiagnosticsImpl.kt

@@ -480,6 +480,12 @@ internal class DeprecatedBinaryModImpl(
     token: KtLifetimeToken,
 ) : KtAbstractFirDiagnostic<PsiElement>(firDiagnostic, token), KtFirDiagnostic.DeprecatedBinaryMod
 
+internal class NestedClassAccessedViaInstanceReferenceImpl(
+    override val symbol: KtClassLikeSymbol,
+    firDiagnostic: KtPsiDiagnostic,
+    token: KtLifetimeToken,
+) : KtAbstractFirDiagnostic<PsiElement>(firDiagnostic, token), KtFirDiagnostic.NestedClassAccessedViaInstanceReference
+
 internal class SuperIsNotAnExpressionImpl(
     firDiagnostic: KtPsiDiagnostic,
     token: KtLifetimeToken,