feat: 新增 i32 / u64 / char 类型 + 字符字面量 "'a'"

src/ast/ast.h

@@ -142,6 +142,7 @@ AstNode* ast_make_call(void* alloc, const char* name, AstNode** args, size_t cou
 AstNode* ast_make_literal_i64(void* alloc, int64_t val, SourceLoc loc);
 AstNode* ast_make_literal_f64(void* alloc, double val, SourceLoc loc);
 AstNode* ast_make_literal_bool(void* alloc, bool val, SourceLoc loc);
+AstNode* ast_make_literal_char(void* alloc, int val, SourceLoc loc);
 AstNode* ast_make_literal_str(void* alloc, const char* val, SourceLoc loc);
 AstNode* ast_make_ident(void* alloc, const char* name, SourceLoc loc);
 AstNode* ast_make_struct_decl(void* alloc, const char* name, AstNode** fields, size_t count, SourceLoc loc);