[IR] Drastically simplify the hierarchy of IR origins

IrStatementOriginImpl and IrDeclarationOriginImpl were made final
classes to simplify the creation of them (a delegate provider was
added) and to optimize performance when comparing the origins by type
and name

compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/linkage/partial/PartialLinkageSupportForLoweringsImpl.kt

@@ -100,7 +100,7 @@ internal class PartialLinkageSupportForLoweringsImpl(
                 startOffset
             }
 
-            else -> if (origin is PartiallyLinkedDeclarationOrigin) {
+            else -> if (origin in PartiallyLinkedDeclarationOrigin.entries) {
                 // There is no sense to take coordinates from the declaration that does not exist in the code.
                 // Let's take the coordinates of the parent.
                 parent.startOffsetOfFirstDenotableIrElement()

compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/linkage/partial/PartiallyLinkedIrTreePatcher.kt

@@ -17,7 +17,7 @@ import org.jetbrains.kotlin.ir.IrStatement
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.declarations.lazy.IrLazyDeclarationBase
 import org.jetbrains.kotlin.ir.expressions.*
-import org.jetbrains.kotlin.ir.expressions.IrStatementOrigin.PARTIAL_LINKAGE_RUNTIME_ERROR
+import org.jetbrains.kotlin.ir.expressions.IrStatementOrigin.Companion.PARTIAL_LINKAGE_RUNTIME_ERROR
 import org.jetbrains.kotlin.ir.expressions.impl.IrCompositeImpl
 import org.jetbrains.kotlin.ir.linkage.partial.*
 import org.jetbrains.kotlin.ir.linkage.partial.PartialLinkageCase.*
@@ -457,7 +457,7 @@ internal class PartiallyLinkedIrTreePatcher(
 
         override fun visitDeclaration(declaration: IrDeclarationBase): IrStatement {
             // Optimization: Don't patch expressions under generated synthetic declarations.
-            return if (declaration.origin is PartiallyLinkedDeclarationOrigin)
+            return if (declaration.origin in PartiallyLinkedDeclarationOrigin.entries)
                 declaration // There are neither expressions nor annotations to patch.
             else {
                 declaration.filterUnusableAnnotations()

compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrBodyDeserializer.kt

@@ -25,6 +25,7 @@ import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.types.impl.*
 import org.jetbrains.kotlin.ir.util.parentAsClass
 import org.jetbrains.kotlin.utils.memoryOptimizedMap
+import kotlin.reflect.full.declaredMemberProperties
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrBlock as ProtoBlock
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrBlockBody as ProtoBlockBody
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrBranch as ProtoBranch
@@ -857,11 +858,10 @@ class IrBodyDeserializer(
         code: () -> Long
     ): S? = if (condition) deserializeTypedSymbol(code(), fallbackSymbolKind, remap = true) else null
 
-    companion object {
-
-        private val allKnownStatementOrigins = IrStatementOrigin::class.nestedClasses.toList()
-
-        private val statementOriginIndex =
-            allKnownStatementOrigins.mapNotNull { it.objectInstance as? IrStatementOriginImpl }.associateBy { it.debugName }
+    private companion object {
+        private val statementOriginIndex = IrStatementOrigin.Companion::class
+            .declaredMemberProperties
+            .mapNotNull { it.get(IrStatementOrigin.Companion) as? IrStatementOrigin }
+            .associateBy { it.debugName }
     }
 }

compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrDeclarationDeserializer.kt

@@ -34,6 +34,7 @@ import org.jetbrains.kotlin.name.Name
 import org.jetbrains.kotlin.types.Variance
 import org.jetbrains.kotlin.utils.*
 import kotlin.collections.set
+import kotlin.reflect.full.declaredMemberProperties
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrAnonymousInit as ProtoAnonymousInit
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrClass as ProtoClass
 import org.jetbrains.kotlin.backend.common.serialization.proto.IrConstructor as ProtoConstructor
@@ -252,7 +253,7 @@ class IrDeclarationDeserializer(
     private inline fun <T> withDeserializedIrDeclarationBase(
         proto: ProtoDeclarationBase,
         setParent: Boolean = true,
-        block: (IrSymbol, IdSignature, Int, Int, IrDeclarationOrigin, Long) -> T
+        block: (IrSymbol, IdSignature, Int, Int, IrDeclarationOrigin, Long) -> T,
     ): T where T : IrDeclaration, T : IrSymbolOwner {
         val (s, uid) = symbolDeserializer.deserializeIrSymbolToDeclare(proto.symbol)
         val coordinates = BinaryCoordinates.decode(proto.coordinates)
@@ -556,7 +557,7 @@ class IrDeclarationDeserializer(
         proto: ProtoFunctionBase,
         setParent: Boolean = true,
         fallbackSymbolKind: SymbolKind,
-        block: (S, IdSignature, Int, Int, IrDeclarationOrigin, Long) -> T
+        block: (S, IdSignature, Int, Int, IrDeclarationOrigin, Long) -> T,
     ): T = withDeserializedIrDeclarationBase(proto.base, setParent) { symbol, idSig, startOffset, endOffset, origin, fcode ->
         val functionSymbol: S = symbol.checkSymbolType(fallbackSymbolKind)
         symbolTable.withScope(functionSymbol) {
@@ -621,7 +622,8 @@ class IrDeclarationDeserializer(
                     isFakeOverride = flags.isFakeOverride,
                 )
             }.apply {
-                overriddenSymbols = proto.overriddenList.memoryOptimizedMap { deserializeIrSymbolAndRemap(it).checkSymbolType(FUNCTION_SYMBOL) }
+                overriddenSymbols =
+                    proto.overriddenList.memoryOptimizedMap { deserializeIrSymbolAndRemap(it).checkSymbolType(FUNCTION_SYMBOL) }
             }
         }
 
@@ -726,7 +728,7 @@ class IrDeclarationDeserializer(
 
     private fun deserializeIrLocalDelegatedProperty(
         proto: ProtoLocalDelegatedProperty,
-        setParent: Boolean = true
+        setParent: Boolean = true,
     ): IrLocalDelegatedProperty =
         withDeserializedIrDeclarationBase(proto.base, setParent) { symbol, _, startOffset, endOffset, origin, fcode ->
             val flags = LocalVariableFlags.decode(fcode)
@@ -794,17 +796,20 @@ class IrDeclarationDeserializer(
             }
         }
 
-    companion object {
-        private val allKnownDeclarationOrigins = IrDeclarationOrigin::class.nestedClasses.toList()
-        private val declarationOriginIndex =
-            allKnownDeclarationOrigins.mapNotNull { it.objectInstance as? IrDeclarationOriginImpl }.associateBy { it.name }
+    private companion object {
+        private val declarationOriginIndex by lazy {
+            IrDeclarationOrigin.Companion::class
+                .declaredMemberProperties
+                .mapNotNull { it.get(IrDeclarationOrigin.Companion) as? IrDeclarationOriginImpl }
+                .associateBy { it.name }
+        }
     }
 
     private fun deserializeIrDeclarationOrigin(protoName: Int): IrDeclarationOrigin {
         val originName = libraryFile.string(protoName)
         return IrDeclarationOrigin.GeneratedByPlugin.fromSerializedString(originName)
             ?: declarationOriginIndex[originName]
-            ?: object : IrDeclarationOriginImpl(originName) {}
+            ?: IrDeclarationOriginImpl(originName)
     }
 
     fun deserializeDeclaration(proto: ProtoDeclaration, setParent: Boolean = true): IrDeclaration {

compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrFileDeserializer.kt

@@ -92,7 +92,7 @@ class FileDeserializationState(
         linker.fakeOverrideBuilder,
         compatibilityMode = moduleDeserializer.compatibilityMode,
         linker.partialLinkageSupport.isEnabled,
-        internationService = linker.internationService
+        internationService = linker.internationService,
     )
 
     val fileDeserializer = IrFileDeserializer(file, fileReader, fileProto, symbolDeserializer, declarationDeserializer)

compiler/ir/serialization.common/src/org/jetbrains/kotlin/backend/common/serialization/IrFileSerializer.kt

@@ -183,7 +183,7 @@ open class IrFileSerializer(
     private fun serializeIrDeclarationOrigin(origin: IrDeclarationOrigin): Int = serializeString(origin.name)
 
     private fun serializeIrStatementOrigin(origin: IrStatementOrigin): Int =
-        serializeString((origin as? IrStatementOriginImpl)?.debugName ?: error("Unable to serialize origin ${origin.javaClass.name}"))
+        serializeString(origin.debugName)
 
     private fun serializeCoordinates(start: Int, end: Int): Long = if (skipPrivateApi) {
         0L