feat: 针对C的代码生成 (#50)

Co-authored-by: Lan_G <2911328695@qq.com>
Reviewed-on: PostGuard/Canon#50

Canon.Core/CodeGenerators/CCodeBuilder.cs

@@ -1,4 +1,5 @@
 using System.Text;
+using Canon.Core.SemanticParser;
 
 namespace Canon.Core.CodeGenerators;
 
@@ -9,6 +10,11 @@ public class CCodeBuilder
 {
     private readonly StringBuilder _builder = new();
 
+    /// <summary>
+    /// 符号表
+    /// </summary>
+    public SymbolTable SymbolTable { get; } = new();
+
     public void AddString(string code)
     {
         _builder.Append(code);