V8 代码缓存支持

¥V8 code cache support

当配置中将 useCodeCache 设置为 true 时，在生成单个可执行准备 blob 期间，Node.js 将编译 main 脚本以生成 V8 代码缓存。生成的代码缓存将成为准备 blob 的一部分，并注入到最终的可执行文件中。当单个可执行应用启动时，Node.js 不会从头开始编译 main 脚本，而是使用代码缓存来加速编译，然后执行脚本，这将提高启动性能。

¥When useCodeCache is set to true in the configuration, during the generation of the single executable preparation blob, Node.js will compile the main script to generate the V8 code cache. The generated code cache would be part of the preparation blob and get injected into the final executable. When the single executable application is launched, instead of compiling the main script from scratch, Node.js would use the code cache to speed up the compilation, then execute the script, which would improve the startup performance.

注意：当 useCodeCache 为 true 时，import() 不起作用。

¥Note: import() does not work when useCodeCache is true.