fix(pproc): 修复预处理器对空行的处理逻辑

- 移除了错误的ENDLINE类型提前返回逻辑
- 将ENDLINE类型的处理移到正确的位置
- 添加了针对条件编译中空行的测试用例

fix(cli): 更新include路径参数的帮助文本

- 修正英文帮助文本为"Add directory to the include search paths"
- 修正中文帮助文本为"添加系统头文件到搜索路径"

src/main.c

@@ -38,7 +38,7 @@ static void setup_argparse(scc_argparse_t *argparse, scc_config_t *config,
         [SCC_HINT_DESCRIPTION] = "A simple C compiler",
         [SCC_HINT_OUTPUT_FILE] = "Output file",
         [SCC_HINT_INPUT_FILE] = "Input source file",
-        [SCC_HINT_INCLUDE_PATH] = "SCC_HINT_INCLUDE_PATH",
+        [SCC_HINT_INCLUDE_PATH] = "Add directory to the include search paths",
         [SCC_HINT_VERBOSE] = "Increase verbosity (can be used multiple times)",
         [SCC_HINT_EMIT_LEX] = "Generate lexer sources tokens and exit",
         [SCC_HINT_EMIT_PP] = "Generate preprocessed tokens and exit",
@@ -50,7 +50,7 @@ static void setup_argparse(scc_argparse_t *argparse, scc_config_t *config,
         [SCC_HINT_DESCRIPTION] = "一个简单的C编译器",
         [SCC_HINT_OUTPUT_FILE] = "输出文件",
         [SCC_HINT_INPUT_FILE] = "输入源文件",
-        [SCC_HINT_INCLUDE_PATH] = "SCC_HINT_INCLUDE_PATH",
+        [SCC_HINT_INCLUDE_PATH] = "添加系统头文件到搜索路径",
         [SCC_HINT_VERBOSE] = "增加详细输出(可多次使用)",
         [SCC_HINT_EMIT_LEX] = "生成`源代码的词法单元`并退出",
         [SCC_HINT_EMIT_PP] = "生成`预处理后的词法单元`并退出",