Add more RuntimeIdentifier information to .NET SDK

[dsplaisted]

• Add NETCoreSdkPortableRuntimeIdentifier to bundled versions. This is the first step to allow us to use a consistent, portable RuntimeIdentifier as the default for the --use-current-runtime parameter. See --use-current-runtime semantics sdk#14296
• Add a NETCoreSdkRuntimeIdentifierChain.txt file to the SDK folder. This is a list of RuntimeIdentifiers compatible with NETCoreSdkPortableRuntimeIdentifier, starting from the best match and walking up the tree. This will allow the workload resolver to better handle RID-specific workload packs, without bringing in additional dependencies (NuGet APIs for processing the RID graph as well as .NET Core APIs for getting the current runtime) which would be difficult to run in an MSBuild resolver that has to run on .NET Framework.

@mhutch @wli3

[am11]

Thanks! I was thinking about deriving it after dotnet/runtime#43804, by sharing the supported platform list and resolution of portable and non-portable RIDs list via arcade repo. However, this approach of reliance on RID graph makes it self-sufficient. (I would have never thought about it) 👍

[dsplaisted]

Thanks! I was thinking about deriving it after dotnet/runtime#43804, by sharing the supported platform list and resolution of portable and non-portable RIDs list via arcade repo. However, this approach of reliance on RID graph makes it self-sufficient. (I would have never thought about it) 👍

Note that this PR doesn't actually solve the problem of setting a different portable RID in source-build. It simply creates a separate property which can be used to do that.

It walks up the RID graph for other reasons, but that alone doesn't tell us which of those RIDs is the right portable RID that we want to use. It might be the same as the ProductMonikerRid, or it might be one or possibly more levels above it in the graph.

[joeloff]

Looks good. People tend to edit text files, so we should just be aware if the RID file is installed and someone edits it, MSI won't remove the file when it uninstalls

[sfoslund]

LGTM