K2. Minor. Rename FirConstExpression to FirLiteralExpression

FirConstExpression is usually confused with "constant" calculations,
while in fact, it just denotes a simple literal expression
and `1 + 1` isn't represented by a FirConstExpression.

^KT-64314 Fixed

plugins/kotlinx-serialization/kotlinx-serialization.k2/src/org/jetbrains/kotlinx/serialization/compiler/fir/checkers/FirSerializationPluginClassChecker.kt

@@ -172,7 +172,7 @@ object FirSerializationPluginClassChecker : FirClassChecker(MppCheckerKind.Commo
     context(CheckerContext)
     private fun FirExpression.isEqualTo(other: FirExpression): Boolean {
         return when {
-            this is FirConstExpression<*> && other is FirConstExpression<*> -> kind == other.kind && value == other.value
+            this is FirLiteralExpression<*> && other is FirLiteralExpression<*> -> kind == other.kind && value == other.value
             this is FirGetClassCall && other is FirGetClassCall -> AbstractTypeChecker.equalTypes(
                 session.typeContext,
                 resolvedType,

plugins/lombok/lombok.k2/src/org/jetbrains/kotlin/lombok/k2/config/annotationUtils.kt

@@ -22,7 +22,7 @@ fun FirAnnotation.getAccessLevel(field: Name = LombokConfigNames.VALUE): AccessL
 private fun FirAnnotation.getArgumentAsString(field: Name): String? {
     val argument = findArgumentByName(field) ?: return null
     return when (argument) {
-        is FirConstExpression<*> -> argument.value as? String
+        is FirLiteralExpression<*> -> argument.value as? String
         is FirEnumEntryDeserializedAccessExpression -> argument.enumEntryName.identifier
         is FirQualifiedAccessExpression -> {
             @OptIn(UnsafeExpressionUtility::class)