Annotate implementations of IDiscardSymbol

Disable tiered compilation for AnalyzerRunner

* Update dependencies from https://github.com/dotnet/arcade build 20200112.1

- Microsoft.DotNet.Arcade.Sdk - 5.0.0-beta.20062.1

* Update dependencies from https://github.com/dotnet/arcade build 20200113.2

- Microsoft.DotNet.Arcade.Sdk - 5.0.0-beta.20063.2

* Update dependencies from https://github.com/dotnet/arcade build 20200115.5

- Microsoft.DotNet.Arcade.Sdk - 5.0.0-beta.20065.5

Use a non-localized category string for DiagnosticDescriptors

Add records

Change the text for the newly added background analysis scope option

Don't offer interpolated string refactoring for const variables

Refactor some dispose code in SymbolUsageAnalysis

1. Make the strings sentence cased
2. Rename "Open Documents And Projects" to "Open documents" as per internal review.

This is not a user facing string, so must not be localized. Additionally, with https://github.com/dotnet/roslyn/pull/38886, we now support bulk severity configuration in editorconfig based on diagnostic category, so the string ought to be a non-localized constant without any spaces.

Fix assertion for the bootstrap compiler

Update readme with recent release notes

Deprecate Workspace.set_Options

Extract out simplification changes

Annotate implementations of IArrayTypeSymbol

Improve diagnostic messages for IDE0060 (remove unused parameter)

Address feedback from https://github.com/dotnet/roslyn/pull/40900

Do not report IDE0059 for reference taken symbols

Update src/Features/Core/Portable/RemoveUnusedParametersAndValues/AbstractRemoveUnusedParametersAndValuesDiagnosticAnalyzer.SymbolStartAnalyzer.BlockAnalyzer.cs