Merge dev15.8.x to dev15.9.x

Updated RoslynNuGetMoniker version for 15.9

Merge dev15.8-preview4 to dev15.8.x

Merge dev15.8.x to dev15.9.x

Turn on loc check for dev15.8.x

Merge dev15.7.x to dev15.8-preview4

Turn on the `windows_loc_status` check for the dev15.8.x and
dev15.8.x-vs-deps branches for CI builds. For PR builds it will continue
to show only when requested.

It is expected that it will fail in these branches until we have our
final loc passes.

Handle null in AssemblyVersion attribute

Remove unused Maddog code

Maddog is no longer used here hence there is no need to generate these
files anymore. Note: their contents were incorrect anyways at this point
which is what lead us to look into whether or not they were being used
anymore.

* Track enclosing symbol in data flow analysis, which might be a field or property.
Code used to assume it was (and typed it as) a method.
Fixes #19845
Fixes #27969

Provide a spellchecking suggestion when someone mispells a constructor.

Reduce IO costs in AnalyzerFileWatcherService

Move to 2.0.7 runtime

Update NamingStyle.cs

Fix type name typo in breaking change docs

Defer reading of the metadata timestamp until later

Produce errors on ref-assignment to byval parameters

`LanguaguageVersionFacts` -> `LanguageVersionFacts`

`LanguaguageVersionFacts` -> `LanguageVersionFacts`

Enable refactorings which were unintentionally removed by 'none' severity

Check receiver escape scope for invocation expressions