Merge dev16.0-preview3 to master

Merge pull request #32813 from jasonmalinowski/fix-metadata-references-not-always-having-file-watchers

Fix bug where references didn't always have a file watcher

Merge dev16.0-preview3 to master

Hardcode the optprof drop to the last known good build

Regression test for 32503

Merge dev16.0-preview3 to master

Issue 32480 - Don't suggest adding braces with interceding compiler directive

Add 16.0-preview3 branches to publish and azure pipelines

this will make clean up to happen faster. this is following existing pattern of remove things faster and show up things slower pattern we have been using on squiggles.

impact on user expierence will be like errors from error list or todo comments on todo list goes away faster when document is removed or project is removed from solution.

mitigating https://github.com/dotnet/roslyn/issues/30577

Account for both parts of partial methods while computing dependent s…

Allow locals, parameters, range variables inside a lambda to shadow names outside the lambda

This issue is fixed. Adding a regression test.

closes #32503

Fixes #32290 
Fixes #32169 
Fixes #32141 
Fixes #32025 

UseLocalFunction should not report diagnostics on invalid decleration code

* Display compiler generated members in raw view.

* Fix dumping of PDBs in DumpAssemblyData

* wip

* FIx for 18409

* Additional fix

* remove commented out code
Co-Authored-By: Nchborl <chborl@users.noreply.github.com>

* Fix spacing issue
Co-Authored-By: Nchborl <chborl@users.noreply.github.com>

* Use default instead of 0
Co-Authored-By: Nchborl <chborl@users.noreply.github.com>

* Respond to feedback

* Add test

Move toolset to the dev16.0p2 compiler

Allow locals, parameters, range variables inside a lambda to shadow names outside the lambda (#32754)

Remove workaround for persistent errors

Allow installing on Dev16.
Allow to specify rootSuffix.
Bump min required VS version to 15.8.
Misc cleanup.

The serialization bug has popped up again. Disabling to get CI green
while Mono takes a look.

https://github.com/mono/mono/issues/10945

This version of the build task can run correctly on .NET Core 3.0. Our
current one is suffering from a private reflection bug that causes the
build tasks to crash on startup. This is the PR which previously fixed
that bug.

https://github.com/dotnet/roslyn/pull/31763