Start to vove the type checker out of the parser

This is needed to check the instantiation of templates.

Author: robertoraggi

packages/cxx-gen-ast/src/gen_ast_h.ts

@@ -228,6 +228,18 @@ private:
     ASTKind kind_;
 };
 
+template <typename T>
+auto make_node(Arena* arena) -> T* {
+  auto node = new (arena) T();
+  return node;
+}
+
+template <typename T>
+auto make_list_node(Arena* arena, T* element = nullptr) -> List<T*>* {
+  auto list = new (arena) List<T*>(element);
+  return list;
+}
+
 [[nodiscard]] inline auto firstSourceLocation(SourceLocation loc) -> SourceLocation { return loc; }
 
 template <typename T>

src/parser/cxx/ast.h

@@ -108,6 +108,18 @@ class AST : public Managed {
   ASTKind kind_;
 };
 
+template <typename T>
+auto make_node(Arena* arena) -> T* {
+  auto node = new (arena) T();
+  return node;
+}
+
+template <typename T>
+auto make_list_node(Arena* arena, T* element = nullptr) -> List<T*>* {
+  auto list = new (arena) List<T*>(element);
+  return list;
+}
+
 [[nodiscard]] inline auto firstSourceLocation(SourceLocation loc)
     -> SourceLocation {
   return loc;