[release/5.0.1xx-preview8] Update dependencies from dotnet/roslyn

[dotnet-maestro]

This pull request updates the following dependencies

From https://github.com/dotnet/roslyn

• Subscription: e251dd77-ab9f-49fc-4299-08d828bd4fbd
• Build: 20200728.1
• Date Produced: 7/28/2020 2:39 AM
• Commit: 8f6d67beadd64b8404935147ed86cdff3d9925bf
• Branch: refs/heads/release/dev16.8-preview1-vs-deps

• Updates:
  • Microsoft.Net.Compilers.Toolset: from 3.8.0-2.20377.5 to 3.8.0-1.20378.1

[dotnet-maestro]

Auto-Merge Status

This pull request has not been merged because Maestro++ is waiting on the following merge policies.

• ✔️ Standard Merge Policies Succeeded - Successful checks: dotnet-sdk-public-ci, dotnet-sdk-public-ci (Build Darwin Build_Release), dotnet-sdk-public-ci (Build Darwin Build_Debug), dotnet-sdk-public-ci (Build Ubuntu_16_04 Build_Release), dotnet-sdk-public-ci (Build Windows_NT_FullFramework Build_Release), dotnet-sdk-public-ci (Build Windows_NT Build_Release), dotnet-sdk-public-ci (Build Windows_NT_TestAsTools Build_Debug), dotnet-sdk-public-ci (Build Ubuntu_16_04 Build_Debug), dotnet-sdk-public-ci (Build Windows_NT_FullFramework Build_Debug), dotnet-sdk-public-ci (Build Windows_NT Build_Debug)
• ✔️ Standard Merge Policies Succeeded - No reviews have requested changes.
• ❌ Standard Merge Policies Some dependency updates are downgrades. Aborting auto-merge.