…red.

…methods.

* Block inheriting from types with required members
* Block calling constructors with invalid required member lists
* Block substituting types with required members in As New, unless the parameterless ctor has SetsRequiredMembers.

* upstream/main: (547 commits)
  Add VerifyMethodBody helper as a replacement of VerifyIL (dotnet#66536)
  don't offer rename for ctor snippet (dotnet#66704)
  Get `ConditionalAttribute` type only once per compilation
  Convert language-specific option types to records (dotnet#66633)
  Enable MSBuild COMM log (dotnet#66708)
  ⚡️Share AssemblyloadTestFixture on Framework (dotnet#66684)
  NRT
  Don't overwrite binary logs in CI (dotnet#66683)
  Fix 'Generate Enum Member' to work in a 'Color Color' case.
  Find bitwise operators accessed through logical operators in FAR
  Semantic snippets - `propg` and `propi` snippets (dotnet#65979)
  NRT
  Properly classify aliases in quick info
  Fix
  Add tests
  Add support for finding collection initialiers with FAR
  Do not suggest replacing lambda with method group if the invoked mehod has `Conditional` attribute
  Revert "Record added node output states as new (dotnet#61575)" (dotnet#66696)
  Record added node output states as new (dotnet#61575)
  Fix formatting issue with convert-to-full-prop
  ...

…a few revealed bugs, handle Nothing converted to a struct with required members.

* Remove Nothing handling to align with C#.
* Remove suppressions of cascading errors.
* Expand unbound test coverage.
* Expand tuple test coverage.

* upstream/main: (2060 commits)
  implement code folding for anonymous objects
  Cleanup/perf in creating member maps. (dotnet#67997)
  Address feedback, clean the use of ILegacyGlobalOptionsWorkspaceService
  Update Publish.json
  Semantic snippets: Add inline statement snippets (dotnet#67819)
  Update VSSDK Build tools version
  Update doc comment
  Address feedback
  Move declaration near reference
  Address feedback
  Avoid stack overflow due to deep recursion on long chain of calls. (dotnet#67913)
  Check ILegacyGlobalOptionsWorkspaceService is null
  test scout queue
  add test
  update editor
  "Where" clause typo fix (dotnet#68002)
  Use `Keyword` helper method instead of hardcoding keyword help terms
  Move the SyntaxTree and SemanticModel action based analyzers to respect context.FilterSpan
  EnC refactoring: Align wrappers with contracts better (dotnet#67967)
  Include EA.RazorCompiler in source build (dotnet#67996)
  ...