Bug 244111

Summary:	Improve "invalid option" error message for malformed flags
Product:	WebKit	Reporter:	Tim Chevalier <tjc>
Component:	JavaScriptCore	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Enhancement	CC:	webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	WebKit Nightly Build
Hardware:	All
OS:	All

Description Tim Chevalier 2022-08-18 17:18:09 PDT

I found the following error message to be confusing:

```
[📦🌐🐱 org.webkit.Sdk GTK@Debug WebKit]$ WebKitBuild/GTK/Debug/bin/jsc  -m JSTests/wasm/gc/arrays.js --useWebAssemblyGC
ERROR: invalid option: --useWebAssemblyGC
```

Eventually I figured out that the flag needs to be `--useWebAssemblyGC=true`. It would be nice if, in general, rather than just "invalid option", the error message included a hint about what the argument for the flag should be.

Comment 1 Radar WebKit Bug Importer 2022-08-25 17:19:15 PDT

<rdar://problem/99162851>