Update ApiCompatBaseline for uapaot for System.Runtime

[ahsonkhan]

Leftover from #29138.

cc @jkotas, @morganbr

[ahsonkhan]

D:\GitHub\Fork\corefx\Tools\ApiCompat.targets(58,5): error : MembersMustExist : Member 'System.ReadOnlySpan.GetPinnableReference()' does not exist in the implementation but it does exist in the contract. [D:\GitHub\Fork\corefx\src\System.Runtime\src\System.Runtime.csproj]
D:\GitHub\Fork\corefx\Tools\ApiCompat.targets(58,5): error : MembersMustExist : Member 'System.Span.GetPinnableReference()' does not exist in the implementation but it does exist in the contract. [D:\GitHub\Fork\corefx\src\System.Runtime\src\System.Runtime.csproj]
D:\GitHub\Fork\corefx\Tools\ApiCompat.targets(72,5): error : ApiCompat failed for 'D:\GitHub\Fork\corefx\bin\Windows_NT.AnyCPU.Debug\System.Runtime\uapaot\System.Runtime.dll' [D:\GitHub\Fork\corefx\src\System.Runtime\src\System.Runtime.csproj]

We have GetPinnabeleReference in corert but I think we have to wait until the ProjectN build update is through: #29202

[jkotas]

You need to first wait for the change to be integrated into https://github.com/dotnet/corert/tree/nmirror

[ahsonkhan]

They are in (as of 9 hours ago): https://github.com/dotnet/corert/blob/nmirror/src/System.Private.CoreLib/shared/System/Span.Fast.cs#L162

[morganbr]

I've confirmed they're in TFS as well. We'll have to wait for the next official build there, which I think will be Sunday night.

[ahsonkhan]

@dotnet-bot test this please

[ahsonkhan]

@dotnet-bot test OSX x64 Debug Build
@dotnet-bot test Linux x64 Release Build

https://github.com/dotnet/corefx/issues/21037
https://github.com/dotnet/corefx/issues/24525