When running Cesium.Compiler with "--ast-dump" then output file is not generated

[pkazakov-dev]

Steps to repro:

1. run Compiler against hello.c with "--ast-dump": dotnet run --project Cesium.Compiler -- .\Cesium.Samples\hello.c --out out.exe --nologo --ast-dump
2. there is no ".\out.exe" file is generated
3. run Compiler against hello.c without "--ast-dump": dotnet run --project Cesium.Compiler -- .\Cesium.Samples\hello.c --out out.exe --nologo
4. there is generated ".\out.exe" file

It seems the new output file is not produced when "--ast-dump" is used.

[ForNeVeR]

Currently, --ast-dump is a undocumented diagnostic option, and thus can formally behave in any way :)

I suggest let's document the option, mark that it won't generate the output file (makes sense IMO — in most cases, you need it when you investigate the parser behavior. Output from the actual codegen is not interesting to you in these cases.

[pkazakov-dev]

OK, that makes sense! It just wasn’t transparent to me.