ffi: new native function format

ast/src/main/kotlin/gay/pizza/pork/ast/Native.kt

@@ -6,23 +6,23 @@ import kotlinx.serialization.Serializable
 
 @Serializable
 @SerialName("native")
-class Native(val form: Symbol, val definition: StringLiteral) : Node() {
+class Native(val form: Symbol, val definitions: List<StringLiteral>) : Node() {
   override val type: NodeType = NodeType.Native
 
   override fun <T> visitChildren(visitor: NodeVisitor<T>): List<T> =
-    visitor.visitNodes(form, definition)
+    visitor.visitAll(listOf(form), definitions)
 
   override fun <T> visit(visitor: NodeVisitor<T>): T =
     visitor.visitNative(this)
 
   override fun equals(other: Any?): Boolean {
     if (other !is Native) return false
-    return other.form == form && other.definition == definition
+    return other.form == form && other.definitions == definitions
   }
 
   override fun hashCode(): Int {
     var result = form.hashCode()
-    result = 31 * result + definition.hashCode()
+    result = 31 * result + definitions.hashCode()
     result = 31 * result + type.hashCode()
     return result
   }