[IR] Unescape identifiers in tree generator more accurately

Simply removing all backticks makes kdocs with code blocks ugly

compiler/ir/ir.tree/gen/org/jetbrains/kotlin/ir/declarations/IrAttributeContainer.kt

@@ -14,9 +14,9 @@ import org.jetbrains.kotlin.ir.IrElement
  * Represents an IR element that can be copied, but must remember its original element. It is
  * useful, for example, to keep track of generated names for anonymous declarations.
  * @property attributeOwnerId original element before copying. Always satisfies the following
- *   invariant: this.attributeOwnerId == this.attributeOwnerId.attributeOwnerId.
+ *   invariant: `this.attributeOwnerId == this.attributeOwnerId.attributeOwnerId`.
  * @property originalBeforeInline original element before inlining. Useful only with IR
- *   inliner. null if the element wasn't inlined. Unlike [attributeOwnerId], doesn't have the
+ *   inliner. `null` if the element wasn't inlined. Unlike [attributeOwnerId], doesn't have the
  *   idempotence invariant and can contain a chain of declarations.
  * @sample org.jetbrains.kotlin.ir.generator.IrTree.attributeContainer
  */

compiler/ir/ir.tree/tree-generator/src/org/jetbrains/kotlin/ir/generator/print/Common.kt

@@ -23,7 +23,7 @@ fun printTypeCommon(generationPath: File, packageName: String, type: TypeSpec):
         .addType(type)
         .build()
         .toString()
-        .replace("`", "")
+        .unbacktickIdentifiers("data", "value", "operator", "constructor", "delegate", "receiver", "field")
         .replace("public ", "")
         .replace(":\\s*Unit".toRegex(), "")
         .replace("import kotlin\\..*\\n".toRegex(), "")
@@ -35,6 +35,14 @@ fun printTypeCommon(generationPath: File, packageName: String, type: TypeSpec):
     return GeneratedFile(getPathForFile(generationPath, packageName, type.name!!), text)
 }
 
+private fun String.unbacktickIdentifiers(vararg identifiers: String): String {
+    var result = this
+    for (identifier in identifiers) {
+        result = result.replace("`$identifier`", identifier)
+    }
+    return result
+}
+
 fun getPathForFile(generationPath: File, packageName: String, typeName: String): File {
     val dir = generationPath.resolve(packageName.replace(".", "/"))
     return File(dir, "$typeName.kt")