Removing the workaround for https://github.com/dotnet/roslyn/issues/42166 identified that IDE0051/IDE0052 were not getting enforced on the build. I will file a follow-up issue to investigate it, but this commit fixes the existing IDE0051/IDE0052 violations in IDE projects where they are set to warning.

That feature has been implemented and Roslyn repo is currently using a toolset which has the compiler with this feature. Additionally, we no longer run analyzers on local builds, so there is no performance impact with this change.

The snippet's curly braces should be escaped due to the `$`. The `$` isn't actually necessary, so I removed it.

Add IDE benchmark project targeting .NET Core

[Dogfooding] Enforce few more code style rules as build warnings in IDE projects

Do not simplify VB ObjectCreationExpression initializers into inferred initializers

Enable CSharpLanguageServiceTest_MultipleResults

Revert unused OptionsCollection in a test - this test does not use this options collection in master branch, but my prior commit in this PR attempted to use it in the test. This leads the test to fail, so I have restored the original semantics of the test and removed an unused local.

Move most of Metadata as Source down to the Features layer

Specialized serialization for options and naming preferences.

Manual fixes for IDE0059 violations for assignments of a non-constant value (we do not offer code fixes to remove such assignments which could have side effects)

# IDE0011: Add braces
csharp_prefer_braces = when_multiline:warning

# IDE0035: Remove unreachable code
dotnet_diagnostic.IDE0035.severity = warning

# IDE0059: Unnecessary assignment to a value
dotnet_diagnostic.IDE0059.severity = warning

Enable IDE0043 (Format string contains invalid placeholder) as build warning for IDE projects (CodeStyle, Features and Workspaces layers)

Implement an LSIF generator

Update src/Workspaces/SharedUtilitiesAndExtensions/Compiler/Core/NamingStyles/Serialization/SymbolSpecification.cs

Closes #43255

Remove skipAnalyzers from vscode tasks

Remove pooled Stopwatch

Fix link in readme

Add 'using' misplacement fixer to code-cleanup

SharedStopwatch already offers a more efficient alternative.