1) Use IDynamicInvocationExpression for VB late bound invocation and C# dynamic invocation.
2) Use IDynamicIndexerAccessExpression for C# dynamic indexer access; not used in VB.
3) Remove IDynamicObjectCreationExpression.MemberName property.
4) Add extension methods on IHasDynamicArgumentExpression to get optional argument name and ref kind for an argument at a given index.

Fixes #20114 and #20122

Fix crash in VisualBasic.Binder.MemberLookup.AddLookupSymbolsInfoInTypeParameter when it is called with Cref TypeParameter. (#21586)

Fixes https://devdiv.visualstudio.com/DefaultCollection/DevDiv/_workitems?id=410932.

The fix mimics the way C# compiler handles Cref TypeParameters in the similar API.

A customer trace on recent 15.3 release shows that `Microsoft.CodeAnalysis.CSharp!Binder.IsAccessibleHelper` is taking up large amount of CPU stacks for LookupSymbols(name) calls from IDE analyzers. This change optimizes the performance of this code path by adding a name check before doing accessibilty checks.

* Compare lines instead of using AssertXml when validating PDBs.

AssertXml doesn't validate ordering.

* Reorder expected PDB XML nodes to match actual order

* Update to the latest Microsoft.DiaSymReader.* packages.

* Enable embedding sources to Windows PDBs

* Clean up Concord exception utilities

* Avoid dependency on IL stream in EnC local slot mapping

* Fix lambda EnC

This is part of the effort to move as much logic from LambdaRewriter
into Analysis as possible. The more logic there is in the Rewriter, the
more difficult it is to find calculation problems until the last
possible moment, and it's also very difficult to calculate useful
information for later analysis passes, like the final debug and closure
IDs for each environment.

* Rename Foo to Goo

* Rename ifoo to igoo

* Add back BOMs

* 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.