IR: add IrClass.getInlineClassRepresentation, serialize/deserialize it

The change in FirDeclarationUtil is needed because in case of unsigned
types loaded from the standard library, the primary constructor for some
reason is not the first, but the second in the list of constructors.

compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/Class.kt

@@ -17,6 +17,11 @@ internal fun PersistentIrGenerator.generateClass() {
     )
     val superTypesField = Field("superTypes", +"List<" + import("IrType", "org.jetbrains.kotlin.ir.types") + ">", superTypeListProto)
     val modalityField = Field("modality", descriptorType("Modality"), modalityProto)
+    val inlineClassRepresentationField = Field(
+        "inlineClassRepresentation",
+        descriptorType("InlineClassRepresentation") + "<" + import("IrSimpleType", "org.jetbrains.kotlin.ir.types") + ">?",
+        inlineClassRepresentationProto
+    )
 
     writeFile("PersistentIrClass.kt", renderFile("org.jetbrains.kotlin.ir.declarations.persistent") {
         lines(
@@ -72,6 +77,7 @@ internal fun PersistentIrGenerator.generateClass() {
                 superTypesField.toPersistentField(+"emptyList()"),
                 +"override var metadata: " + MetadataSource + "? = null",
                 modalityField.toPersistentField(+"modality"),
+                inlineClassRepresentationField.toPersistentField(+"null"),
                 +"override var attributeOwnerId: " + IrAttributeContainer + " = this",
             ),
             id,
@@ -86,6 +92,7 @@ internal fun PersistentIrGenerator.generateClass() {
             modalityField,
             typeParametersField,
             superTypesField,
+            inlineClassRepresentationField,
         )()
     })
 
@@ -96,5 +103,6 @@ internal fun PersistentIrGenerator.generateClass() {
         modalityField,
         typeParametersField,
         superTypesField,
+        inlineClassRepresentationField,
     )
-}
+}

compiler/ir/ir.tree.persistent/generator/src/org/jetbrains/kotlin/ir/persistentIrGenerator/PersistentIrGenerator.kt

@@ -3,11 +3,11 @@
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
+@file:Suppress("MemberVisibilityCanBePrivate")
+
 package org.jetbrains.kotlin.ir.persistentIrGenerator
 
 import java.io.File
-import java.lang.IllegalStateException
-import java.lang.StringBuilder
 
 internal interface R {
     fun text(t: String): R
@@ -156,6 +156,11 @@ internal object PersistentIrGenerator {
 
     val visibilityProto = Proto(null, "visibility", +"Long", DescriptorVisibility)
     val modalityProto = Proto(null, "modality", +"Long", descriptorType("Modality"))
+    val inlineClassRepresentationProto = Proto(
+        "IrInlineClassRepresentation", "inlineClassRepresentation",
+        import("IrInlineClassRepresentation", protoPackage, "ProtoIrInlineClassRepresentation"),
+        descriptorType("InlineClassRepresentation") + "<" + import("IrSimpleType", "org.jetbrains.kotlin.ir.types") + ">"
+    )
 
     val isExternalClassProto = Proto(null, "isExternalClass", +"Long", +"Boolean")
     val isExternalFieldProto = Proto(null, "isExternalField", +"Long", +"Boolean")
@@ -180,6 +185,7 @@ internal object PersistentIrGenerator {
         variableProto,
         visibilityProto,
         modalityProto,
+        inlineClassRepresentationProto,
         isExternalClassProto,
         isExternalFieldProto,
         isExternalFunctionProto,