move down diagnostic analyzer executor down to workspace layer since all requires one now lives in workspace layer.

Share 'generated-code' logic between the compiler and IDE.

Merge master into post-dev15

# Conflicts:
#	src/Compilers/CSharp/Test/Semantic/Semantics/OutVarTests.cs
#	src/EditorFeatures/TestUtilities/Remote/InProcRemostHostClient.cs
#	src/VisualStudio/Core/Next/Remote/JsonRpcClient.cs
#	src/VisualStudio/Core/Next/Remote/ServiceHubRemoteHostClient.cs

Remove code that is no longer necessary now that a compiler bug has been fixed.

Filter out light bulb actions with duplicate titles.
Fixes #16024

Run NavigateTo unit tests in OOP as well.

Run FindRefs unit tests in OOP as well.

Allow build output to be redirected externally

Fix issue with inline-formatting changing indentation of multi-line constructs
Fixes #16198

Add ref-support for generating fields/properties.

Fix issue that prevented us from offering rename-file options.
Fixes #16284

Add support for generating methods that return-by-ref.
Fixes #16398

Pass along the value that was unexpected when we encounter one.

Report use-site diagnostics if System.ValueTuple base type is an error type

Properly generate type syntax for tuples with less than arity-2.
Fixes #16793

Guard against serialization failure of Encoding

* remove superfluous use of local function

* add preliminary stack depth finder

* vs changed files

* Use shorter version number for s.c.immutable

Allow emitting debugging symbols via high level scripting APIs

Merging on behalf of @DanMcNultyDev