worker: enable passing command line flags

This PR adds the ability to provide Workers with their own
execArgv flags in replacement of the main thread's execArgv. Only
per-Isolate/per-Environment options are allowed. Per-Process options
and V8 flags are not allowed. Passing an empty execArgv array will
reset per-Isolate and per-Environment options of the Worker to their
defaults. If execArgv option is not passed, the Worker will get
the same flags as the main thread.

Usage example:
```
const worker = new Worker(__filename, {
    execArgv: ['--trace-warnings'],
});
```

PR-URL: https://github.com/nodejs/node/pull/25467
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/env.h b/src/env.h
index fdd5c2382c..711d07963a 100644
--- a/src/env.h
+++ b/src/env.h
@@ -394,6 +394,7 @@ class IsolateData {
   inline uint32_t* zero_fill_field() const;
   inline MultiIsolatePlatform* platform() const;
   inline std::shared_ptr<PerIsolateOptions> options();
+  inline void set_options(std::shared_ptr<PerIsolateOptions> options);
 
 #define VP(PropertyName, StringValue) V(v8::Private, PropertyName)
 #define VY(PropertyName, StringValue) V(v8::Symbol, PropertyName)