Dynamic array syntax [...]Type; make entities private with a prefix of _; fix extension checking

src/entity.c

@@ -98,6 +98,15 @@ struct Entity {
 
 gb_global Entity *e_context = NULL;
 
+bool is_entity_name_exported(Entity *e) {
+	GB_ASSERT(e != NULL);
+	String name = e->token.string;
+	if (name.len == 0) {
+		return false;
+	}
+	return name.text[0] != '_';
+}
+
 
 Entity *alloc_entity(gbAllocator a, EntityKind kind, Scope *scope, Token token, Type *type) {
 	Entity *entity = gb_alloc_item(a, Entity);