Fixes https://devdiv.visualstudio.com/DevDiv/_workitems?id=481125

* Update PDB converter to 1.1.0-beta1-62221-01

* Enable more conversion tests

* Closes #18171

* ReadOnly Tuple Structs

* Closes #18172

* made children not to return null and reorder children in evaluation order

* added some verification

* fixed formatting

* fixed ordering

* removed temp variable.

Fixes #22679. Fixes #7397. Related to #22029.

Do not expose implicit IInstanceReferenceExpression in an IDelegateCreationExpression targeting static method. (#22706)

Fixes #15513.

Fixes #21021

Addresses Preview and Documentation items from #22719

Ensure complete information is consistently captured in a bound tree for an explicit C# conversion implicitly applied by compiler. (#22703)

Fixes #7299. Fixes #19878

Address PR feedback and change the starting value for the enums to be 0 to follow .NET coding guidelines

Fixes #22692

1. ArgumentKind.None
2. BinaryOperatorKind.None
3. BranchKind.None
4. CaseKind.None
5. DoLoopKind.None
6. LoopKind.None
7. UnaryOperatorKind.None

Fixes #22694

See [OperationExtensions.GetRootOperation](http://source.roslyn.io/#Microsoft.CodeAnalysis/Operations/OperationExtensions.cs,91) API.
This API existed from original IOperation prototype, has never been implemented and always returns null.

Fixes #22691

Add tests to make sure virtual slot is set correctly for parent types of types that have modreq members or implementations (#22646)

* Add tests to make sure virtual slot is set correctly for parent types of types that have modreq members or implementations

* PR comments

Fixes #22650

Be resilient to getting busy messages back from sqlite while retrieving data.