1. Add Locals property to ILoopStatement
2. Remove IterationVariable from foreach loops and VB ForTo loops.
3. Add InvalidCondition to Do loops for VB error cases.
4. Rename property AddLoopBottomExpressionList to NextVariables
5. Add relevant unit tests
6. Remove ISyntheticLocalReferenceExpression and SyntheticLocalKind

Remove IsDeclaration: False from ILocalReferenceExpression and IFieldReferenceExpression. Adding back is tracked by #21798

Fixes #8882

1. Flatten the loop statement hierarchy to only derive from ILoopStatement
2. Separate out do loops and while loops
3. Separate out the C# and VB for loops due to different semantics and syntax.

Fixes #21282

1. Add IsChecked flag for IIncrementExpression and ICompoundAssignmentExpression
2. Add back VB specific binary operator kinds
3. Add more unit tests and fix baselines of existing tests

Moved IFixedStatement internal until we have time to review the API. NoneOperation will be used in its place.

This implements a bunch of changes to the IOperation representation for binary operator, unary operator and increment expressions.

1. #8834: Simplify `UnaryOperatorKind` to only contain the operator kind values instead of a matrix of operator and operand kinds.
2. #8835: Simplify `BinaryOperatorKind` in similar manner as above.
3. #8825: Add `IUnaryOperatorExpression.IsChecked` flag. Cyrus has already added the `IUnaryOperatorExpression.IsLifted` flag.
4. #8846: Add `IBinaryOperatorExpression.IsChecked` and `IBinaryOperatorExpression.IsCompareText` flags Cyrus has already added the `IBinaryOperatorExpression.IsLifted` flag.
5. #21283: Add `IIncrementExpression.IsDecrement` and `IIncrementExpression.IsPostfix` flags and remove PostFix/Prefix Increment/Decrement from `UnaryOperatorKind` enum.

This change also fixes #8848 and #8843 as the matrix operation kind enums no longer exist.

Merged on behalf of @svick 
Thanks for the contribution!

* Expose if a Binary/Unary operator was 'Lifted' at the IExpression level.

* Update public API.

* Share computed value.

* Remove unnecessary extension.

* Update test code.

* Remove extension method.

* Fixup tests.

* Fixup tests.

* Fixup tests.

* Fix instances of Invalid operations with nullable

* Compound assignments also need to state if they're lifted.

* Move tests.

* Move tests.

* Move tests.

* Simplify comment.

* Case things consistently.

* Use F instead of Foo.  Because Foo is bad.

* Changing the dumper to get of calling base.Visit when not needed

* Getting rid of cobyrc file

* Adding copyright header

* fixing merge conflict

Add IOperation support for variations of object creation expressions (type parameter, nopia and dynamic)

Fixes #20119 and #20491

* Change the IOperation unit test dump format for child nodes

* fixing the newly merged tests.