Remove perf from builds (dotnet#3654)

Update dependencies from https://github.com/dotnet/core-setup build 2…

…0190906.20 (dotnet#3608)

- Microsoft.NET.HostModel - 3.0.0-rc1-19456-20

Disable symbol creation for now (dotnet#3580)

* Disable symbol creation for Microsoft.NET.Build.Tasks

* Update Microsoft.NET.Build.Extensions.Tasks.csproj

Update dependencies from https://github.com/dotnet/core-setup build 2…

…0190805.07 (dotnet#3507)

- Microsoft.NET.HostModel - 3.0.0-preview8-28405-07

Merge pull request dotnet#3412 from elinor-fung/updateHostModelVersio…

…n-release

Update Microsoft.NET.HostModel version

Merge pull request dotnet#3392 from dsplaisted/fix-duplicate-framework

Don't write the same framework multiple times to RuntimeConfig.json

Merge pull request dotnet#2986 from dsplaisted/platforms-privateassets

Mark implicit platforms package reference as PrivateAssets

Merge pull request dotnet#2273 from johnbeisner/FixPerformance

Putting back the 'perf' property switch

Merge pull request dotnet#2194 from dsplaisted/self-contained-publish

Support overriding MSBuildProjectExtensionsPath for a specific project via global properties

Merge pull request dotnet#1939 from natidea/updateSupportedFx

Add .NET Core 2.1 to list of supported target frameworks