Add back support for non MEF imported completion providers

Detect a new pattern for when a ??= expression can be suggested.

Ensure that hidden analyzer escalated to non-hidden severity through …

Restrict the locations we show some refactorings in

Fix indentation when converting to simple-using-statements.

* Enable nullable reference types for SymbolExtensions

* Add missing annotation

Port populate switch analzyer and fixer to shared layer

Ensure that hidden analyzer escalated to non-hidden severity through editorconfig setting are executed during Full solution analysis (FSA)

Fixes #42353

Improve determination about which parameters already match in add-param.

Track changed option keys in global option service so the serializabl…

Fix integration test failures by only adding serializable option keys in the changed options keys for the solution snapshot. Also updated the newly added unit test to explicitly test this scenario that was caught by integration tests.

Port QualifyMemberAccess analyzer and fixer to shared layer

Fix a bug in conversion classification that improperly hides a switch expression conversion when there is a built-in explicit conversion (#42339)

This bug results in the compiler crashing or producing bad code in some scenarios.
Fixes #42331

Annotate remaining syntax list types

There are two problems here, the first of which is the most important.

First, certain data flow analyses use "normalization" to adjust an existing
state variable for more variables declared after that state was created.
The default behavior is to extend that state to the "top" state, meaning
the starting state for that data flow analysis. This is usually the
right extension. However, some analysis requires extending the
variables the other way, to the bottom state. This PR adds functionality
for that customization.

The second problem is that data flow for local functions may include
variables that are not captured. This is by filtering the transfer function
to only include captured variables.

Fixes fixes #41600

Support executing generate-compiler-code.ps1 on Linux using Powershell Core

Fix issues with VB's ParseTrailingTrivia helper.

Co-Authored-By: NJared Parsons <jaredpparsons@gmail.com>

Port UseThrowExpression analyzer/fixer to shared layer

Port C# AddBraces analyzer/fixer to shared layer

Keep parens around conditional exprs as they effect semantics.

Wrap on lower precedence binary operations.

Update docs to make lifetimes clear

Do not offer 'use auto prop' on serializable types.

Add test validating behavior.