mruby-compiler: convert new_true and new_false to always use variable-sized nodes

Complete the conversion of boolean literal nodes by:

1. Convert new_true to always use variable-sized nodes and inline new_true_var
   directly into the function, eliminating function call overhead
2. Remove obsolete NODE_TRUE case from traditional codegen() and inline
   codegen_true function into gen_true_var for cleaner code
3. Apply the same optimizations to new_false - inline new_false_var and
   remove obsolete NODE_FALSE case and codegen_false function
4. Clean up unused functions and forward declarations

Both true and false literals now always use the variable-sized node path
with direct OP_LOADT/OP_LOADF instruction generation, eliminating
conditional branching and function call overhead.

Co-authored-by: Claude <noreply@anthropic.com>

mrbgems/mruby-compiler/core/codegen.c

@@ -3915,17 +3915,6 @@ codegen_nil(codegen_scope *s, node *tree, int val)
   gen_load_op1(s, OP_LOADNIL, val);
 }
 
-static void
-codegen_true(codegen_scope *s, node *tree, int val)
-{
-  gen_load_op1(s, OP_LOADT, val);
-}
-
-static void
-codegen_false(codegen_scope *s, node *tree, int val)
-{
-  gen_load_op1(s, OP_LOADF, val);
-}
 
 static void
 codegen_lvar(codegen_scope *s, mrb_sym sym, int val)
@@ -5568,15 +5557,15 @@ gen_nil_var(codegen_scope *s, node *varnode, int val)
 static void
 gen_true_var(codegen_scope *s, node *varnode, int val)
 {
-  /* Use traditional true codegen logic */
-  codegen_true(s, NULL, val);
+  /* Generate OP_LOADT instruction for true literal */
+  gen_load_op1(s, OP_LOADT, val);
 }
 
 static void
 gen_false_var(codegen_scope *s, node *varnode, int val)
 {
-  /* Use traditional false codegen logic */
-  codegen_false(s, NULL, val);
+  /* Generate OP_LOADF instruction for false literal */
+  gen_load_op1(s, OP_LOADF, val);
 }
 
 static void
@@ -6655,14 +6644,6 @@ codegen(codegen_scope *s, node *tree, int val)
     codegen_nil(s, tree, val);
     break;
 
-  case NODE_TRUE:
-    codegen_true(s, tree, val);
-    break;
-
-  case NODE_FALSE:
-    codegen_false(s, tree, val);
-    break;
-
   case NODE_ALIAS:
     codegen_alias(s, tree, val);
     break;

mrbgems/mruby-compiler/core/parse.y

@@ -49,8 +49,6 @@ static int toklen(parser_state *p);
 /* Forward declarations for variable-sized simple node functions */
 static node* new_self_var(parser_state *p);
 static node* new_nil_var(parser_state *p);
-static node* new_true_var(parser_state *p);
-static node* new_false_var(parser_state *p);
 static node* new_const_var(parser_state *p, mrb_sym symbol);
 
 /* Forward declarations for variable-sized advanced node functions */
@@ -558,20 +556,28 @@ new_nil(parser_state *p)
 static node*
 new_true(parser_state *p)
 {
-  if (p->var_nodes_enabled) {
-    return new_true_var(p);
-  }
-  return list1((node*)NODE_TRUE);
+  size_t total_size = sizeof(struct mrb_ast_true_node);
+  enum mrb_ast_size_class class = size_to_class(total_size);
+
+  struct mrb_ast_true_node *n = (struct mrb_ast_true_node*)parser_alloc_var(p, total_size, class);
+
+  init_var_header(&n->hdr, p, NODE_TRUE, class);
+
+  return cons_head((node*)NODE_VARIABLE, (node*)n);
 }
 
 /* (:false) */
 static node*
 new_false(parser_state *p)
 {
-  if (p->var_nodes_enabled) {
-    return new_false_var(p);
-  }
-  return list1((node*)NODE_FALSE);
+  size_t total_size = sizeof(struct mrb_ast_false_node);
+  enum mrb_ast_size_class class = size_to_class(total_size);
+
+  struct mrb_ast_false_node *n = (struct mrb_ast_false_node*)parser_alloc_var(p, total_size, class);
+
+  init_var_header(&n->hdr, p, NODE_FALSE, class);
+
+  return cons_head((node*)NODE_VARIABLE, (node*)n);
 }
 
 /* (:alias new old) */
@@ -1263,31 +1269,7 @@ new_nil_var(parser_state *p)
   return cons_head((node*)NODE_VARIABLE, (node*)n);
 }
 
-static node*
-new_true_var(parser_state *p)
-{
-  size_t total_size = sizeof(struct mrb_ast_true_node);
-  enum mrb_ast_size_class class = size_to_class(total_size);
 
-  struct mrb_ast_true_node *n = (struct mrb_ast_true_node*)parser_alloc_var(p, total_size, class);
-
-  init_var_header(&n->hdr, p, NODE_TRUE, class);
-
-  return cons_head((node*)NODE_VARIABLE, (node*)n);
-}
-
-static node*
-new_false_var(parser_state *p)
-{
-  size_t total_size = sizeof(struct mrb_ast_false_node);
-  enum mrb_ast_size_class class = size_to_class(total_size);
-
-  struct mrb_ast_false_node *n = (struct mrb_ast_false_node*)parser_alloc_var(p, total_size, class);
-
-  init_var_header(&n->hdr, p, NODE_FALSE, class);
-
-  return cons_head((node*)NODE_VARIABLE, (node*)n);
-}
 
 static node*
 new_const_var(parser_state *p, mrb_sym symbol)