implement native type compilation

bir/src/main/kotlin/gay/pizza/pork/bir/IrDefinitionType.kt

@@ -6,5 +6,6 @@ import kotlinx.serialization.Serializable
 enum class IrDefinitionType {
   Variable,
   CodeFunction,
-  NativeFunction
+  NativeFunction,
+  NativeType,
 }

bir/src/main/kotlin/gay/pizza/pork/bir/IrNativeDefinition.kt

@@ -3,6 +3,6 @@ package gay.pizza.pork.bir
 import kotlinx.serialization.Serializable
 
 @Serializable
-data class IrNativeDefinition(var form: String, var definitions: List<String>) : IrCodeElement() {
+data class IrNativeDefinition(var kind: IrNativeDefinitionKind, var form: String, var definitions: List<String>) : IrCodeElement() {
   override fun crawl(block: (IrElement) -> Unit) {}
 }

bir/src/main/kotlin/gay/pizza/pork/bir/IrNativeDefinitionKind.kt

@@ -0,0 +1,9 @@
+package gay.pizza.pork.bir
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+enum class IrNativeDefinitionKind {
+  Function,
+  Type
+}