1. Ensure correct syntax nodes and implicit state are used for IArgument nodes matching OmittedArgumentSyntax. Fixes #22486.
2. Ensure correct argument kind is associated with synthesized arguments within query expressions. Fixes #22066.
3. Ensure the invariant that “each syntax node has at most one corresponding explicit IOperation node” is met for all test scenarios we have at the moment. In order to achieve this the following changes are made:
-mark some synthesized bound nodes as compiler generated.
-for assignment statements, ensure that ISimpleAssignmentExpression and ICompoundAssignmentExpression nodes are marked as Implicit because they are sharing syntax node with containing IExpressionStatement and VB doesn’t have a concept of an assignment expression.
-for throw statements, ensure that IThrowExpression node is marked as Implicit because it is sharing syntax node with containing IExpressionStatement and VB doesn’t have a concept of a throw expression.
-for Add/RemoveHandler statements, ensure that IEventAssignmentExpression node is marked as Implicit because it is sharing syntax node with containing IExpressionStatement and VB doesn’t have a concept of an event assignment expression.
-ensure that receivers for IPropertyReferenceExpression representing references to query range variables are marked as implicit.
-ensure that IPropertyReferenceExpression and IParameterReferenceExpression nodes representing references to query range variables are associated with correct syntax nodes.
-ensure that return statements and blocks in query lambdas are marked as implicit.
-for IInterpolatedStringText node, ensure the underlying ILiteralExpression is marked as implicit because it is sharing syntax node with its parent.

Address more feedback from design meeting and expose IOperation.IsExpression and IOperation.IsStatement properties

Microsoft.CodeAnalysis.Semantics renamed to Microsoft.CodeAnalysis.Operations

The use of Assert.True() is confusing as you end up with:

Expected: [set]
Actual: [another set]
Expected: True
Actual: False

This dispenses of the second expected/actual.

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

* added some verification

* fixed formatting

* fixed ordering

* removed temp variable.

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

Fixes #15513.

Addresses Preview and Documentation items from #22719

1. Rename `ILocalInitializer` to `IVariableInitializer`
2. Refactor OperationFactory methods
3. Change type of `IVariableDeclaration.Initializer` from `IOperation` to `IVariableInitializer`

Fixes #22429

* Adding cobyrc file for testing

* Adding isImplicit info to ioperation tests

* Adding Language name to the test dumper

* Formatting change to test dumper

* Removing cobyrc file

* Fixing more tests

* Resolving conflicts

* Moving the language to assert check

* Resolving conflicts

* Reacting to merge conflict

For v1, we have decided to expose this as assignment with regular conversion data. In v2, we will expose richer API with deconstruction method and also match language specification on whether this is exposed as a conversion or not. This is tracked with #22477.

Fixes #19924

Fixes #22006

Fixes #21297 and #22004

Fixes #22008

There might be some more API changes based on the open issues mentioned in #22008

Fixes #22265

Fixes #22007

Fixes #22003 and #21296.

Fixes https://github.com/dotnet/roslyn/issues/21748

I also found that Range and Relational case clause have no tests in VB. Additionally, I also marked all OperationAnalyzerTests with CompilerTrait attribute so they don't get skipped in local trait based testing.
Fixes #22129

1. Fix test issues
2. Remove IHasDynamicArgumentsExpression interface and move the Arguments property from it to individual IDynamicXXXExpression nodes.
3. Adjust the extension methods for GetArgumentName and GetArgumentRefKind accordingly.