Generate Nuget Packages for ILToNative

[gkhanna79]

This change does the following only for Windows:

1. Generate Microsoft.Dotnet.ILToNative and Microsoft.Dotnet.ILToNative.Development nuget packages. The latter contains PDBs.

2. Get ILToNative.exe to be dropped to the bin folder. Also added a task to create ILToNative.dll from ILToNative.exe so that CoreConsole can launch the driver.

3. Unify all product drops to be dropped under bin\product\ - currently they were getting dropped to random locations (native components would go in the intended location but managed would not).

4. Package Runtime.lib and System.Private.CoreLib.dll within the Nuget packages.

@jkotas @schellap Can you please take a look?

[schellap]

LGTM

[MichalStrehovsky]

I'm a bit worried about the changes to dir/dirs. I've been trying to keep these files very close to how they look in the CoreFX repo. Is this how they do NuGet packages there?

[gkhanna79]

The key change in dir.props is how the name of the subfolder, where binaries need to be binplaced, is computed. Today, native builds places things under bin/product/winnt_x64_debug, while managed build puts stuff under bin/wint_{amd64|AnyCPU}_Debug.

For a given build, it is more structured to have all product binaries in a single location independent of how they were built (e.g. Product is sibling of tests folder under bin that gets tests binplaced). This is similar to how the CoreCLR repo also has things setup. It also makes it easier for NuSpec to pickup the binaries in a consistent location for packaging.

[MichalStrehovsky]

That makes sense, thanks!

In retrospect, my comment should have been "changes to src/dirs.proj".

Maybe instead of making a copy of ILToNative.exe to ILToNative.dll, we can just build it as a library? I'm not sure if we have any other use for the EXE right now (everyone developing on Windows is using the ILToNative.exe produced by the desktop project anyway and having just one EXE project would at least reduce confusion for new people).

[gkhanna79]

I considered making the change to lib for ILToNative but for now, it is not imperative. I will assign an issue to myself to clean that up.

[jkotas]

LGTM